Get ready to welcome spring produce with these pistachio rhubarb tarts! A wonderful gluten free dessert made with pistachio tart shells filled with a rhubarb compote brightened up with orange, rose, and cardamom then topped with torched meringue. Nothing could be better this spring!

A close up shot of one of the pistachio rhubarb tarts on a stack of small white plates

What Pairs Well with Rhubarb?

Rhubarb is my favorite springtime produce. Whenever I see vibrant pink/red rhubarb in the grocery store I know that spring has sprung and winter is behind us. Rhubarb is very very sour, so when you bake with rhubarb, it always needs sugar to sweeten the deal. Pistachios always go great with rhubarb because as a fattier nut, it helps cut down that sourness and also provides a contrasting green color component to the tart. Adding the rose gives it a pop of floral, but remember that a little rose goes a long way. These pistachio rhubarb tarts are also a perfect gluten and dairy free dessert.

The History of Rhubarb

Despite being used for many dessert recipes, rhubarb is actually a vegetable and was not used for culinary purposes! Rhubarb roots were first used by the Chinese five thousand years ago as a laxative and wouldn’t hit the kitchens until the 1820’s. In fact, it was one brave woman in London with a knack for tarts and home grown rhubarb who decided she was up for the pastry challenge. The combination of sugar becoming affordable and rhubarb being available before any spring vegetables made it a recipe for success after hard winters.

Despite how delicious the rhubarb is, the leaves are actually lethal. Rhubarb leaves have high concentrations of oxalic acid which can be lethal to humans in certain doses. Unfortunately, the English learned that the hard way! Read a whole lot more on rhubarb here!

A few pistachio rhubarb tarts on a small wire rack on top of ripped out book pages

Pistachio Rhubarb Tarts Ingredients

Pistachios: Use unroasted for this nutty bake. If you buy them with shells, make sure to remove the shells. If you buy salted, omit the salt from the tart shell recipe.
Rhubarb: Always pick the most vibrant ones you can find for this fruity bake. If your grocery store’s rhubarb is sub par in color, you can always adjust with food coloring.
Rosewater: Completely optional but I love the floral component. You can get rosewater in most liquor stores.

Major Allergens Present: Nuts, eggs

Equipment Needed

Food processor: Used to make .the pistachio tart shells. Alternatively, you can use a rolling pin and ziplock bag. Make sure those nuts are super fine though.
4″ fluted tart shells: Used to bake the pistachio tart shell in. You will want to spray these heavily as the crust has a tendency to stick!
Hand or stand mixer: Used to make the meringue. For a hand mixer you will use the beaters, and for a stand mixer you will use the whip.
Piping bag and tip: Optional if you want to do any pipework on top with the meringue. I use industry sized piping bags which I buy online.
A blowtorch: Used to torch the meringue. You can either buy one from a specialty kitchenwares store or from a hardware store. I promise you they are cheaper and actually better from the hardware store.

An overhead shot of four pistachio rhubarb tarts with dried rose petals and pistachios scattered about

How to Make Pistachio Rhubarb Tarts Recipe:

What are pistachio tarts made out of?

A wonderfully refreshing dessert to bake this spring, these mini rhubarb tarts have three components. The first is the pistachio tart shell made with just pistachios, almond flour, sugar, and eggs making this dessert both naturally gluten free and dairy free. The shell is filled with a rhubarb compote flavored with orange, cardamom, and rose. It’s finally topped with a torched meringue. This is one great dessert to serve for Mother’s Day or Easter dinner.

Make the pistachio tart shell:

Start by grinding everything except the egg in a food processor until super fine then add the egg in with a spatula until a sort of dough forms. When it comes to shaping in your tart tins, wet your fingers first to prevent sticking then start pressing it into the tins. I’ll start with the bottom then pinch it into the sides. When baking, rotate halfway through for even coloring and baking. It’s ready to come out of the oven when the edges turn brown. Remove as soon as you can handle the tarts. The longer they sit in the tin, the harder they are to come out.

Make the rhubarb compote:

With the sourness of the rhubarb we need to add a decent amount of sugar. This compote still allows for the tartness of the rhubarb to come through, however, if you prefer something sweeter, go ahead and increase the sugar by 10-15%. This method uses a cooked sugar method which is best for produce with a low water content. Start by mixing the sugar with just enough water to make wet sand, and allow it to cook until the bubbles become slow and lethargic.

Once the sugar is at temp, throw in the diced up rhubarb and immediately mix. This will be tough because the sugar will immediately start to cool down and thicken. Keep stirring until everything settles down and the sugar thins out. At this point we add the extra flavor enhancers (orange, cardamom, optional rosewater), and reduce the heat to medium. Allow it to cook until almost all the juices have cooked out. Make sure to stir every other minute otherwise the bottom will burn. If your rhubarb was not naturally a beautiful color, then add in a few drops of red and/or pink food coloring to brighten it up.

Whip up the swiss meringue:

There are three types of meringues: American, Swiss, and Italian. Each one is cooked differently. American style is not cooked at all and is the least stable. Swiss style has the egg whites and sugar cooked until the sugar dissolves and has a medium stability. And Italian style cooks the sugar to 250*F and is the most stable. Depending on what you’re making depends on what stye of meringue you should use. Since we are just decorating, Swiss works well here. See my post on how to make meringue for more info.

Decorating with meringue is of course optional but highly recommended; it’s sweetness helps cut the tartness of the rhubarb. Decorating with meringue is of course optional but highly recommended. You simply warm the whites and sugar over a double boiler until the sugar dissolves whisking minimally. I will just stick my fingers in and feel if there any sugar granules. Then you whip on high speed until stiff peaks form. You can’t overwhip Swiss meringue, but you do need to keep it in motion until you use it otherwise it will become blocky. How you pipe and decorate is your choice.

Finish the pistachio rhubarb tarts:

Once you’ve finished all of the components, it is time to compose the tart! Evenly distribute the compote between the tarts. After the compote is added, decorate with the meringue. You can pipe with a piping bag and tip or you can spoon it on rustic style. Don’t forget to bust out the blowtorch if you are equipped (the best part in my opinion!). To torch, use even fluid motions. Less is more and you can always go back over it. Adorn with roughly chopped pistachios and enjoy same or next day.

A close up shot of one of several pistachio rhubarb tarts

Help Making Pistachio Rhubarb Tart:

How to Make Swiss Meringue

For more detailed information on how to make meringue, see this post.
Use fresh egg whites as opposed to carton egg whites. Fresh will always whip up better; in fact, sometimes carton egg whites don’t whip up at all.
Make sure no fat gets in the bowl or on your whip attachment! Fat (such as cream, butter, or egg yolks) will always destroy a beautifully whipped meringue. You can wipe the bowl and attachment with a vinegar dampened paper towel.
You can’t over-whip Swiss or Italian meringue so turn that mixer on high and let it rip! However, once you have it going it must be kept in constant motion or else it will be less smooth and more chunky. If I’m not quite ready for it yet, I’ll turn my mixer down to 1-2 speed (low) until I am.
When warming the whites and sugar together, just warm it until the sugar is dissolved. Help it along by whisking now and again. I will use my fingers to check for any remaining sugar crystals.

How to Fill and Use a Piping Bag:

Insert the piping tip and cut a hole accordingly. Push some of the bag into the tip to prevent any leakage.
Fold the the top quarter to third of the bag over and hold the bag there. Spatula your batter into the bag wiping the spatula with your hand through the bag.
Fold the top back over and hold the top of the bag with your non-dominant hand. With large piping bags I will actually twist the end and put under my arm pit for safe keeping.
Squeeze the center of the bag and twist. This your pressure point and your control point of the bag. The further from the tip, the more strenuous and less control you have over the bag.
Use the meat of your hand to then squeeze out the contents. Release to stop.

Enhancing This Pistachio Rhubarb Tart Recipe:

Fold in some fresh strawberries after the compote has cooled for a strawberry rhubarb tart.
Instead of orange, rose, and cardamom, use lemon and basil.
Use a different nut if you do not like pistachio! Almond, cashew, and walnut would both go great.

How to Store and Freeze Pistachio Rhubarb Tarts:

Store the compote separately in a container in the fridge for up to 1 week or in the freezer for up to 3 months.
Keep the tart shells at room temperature in a sealed container for up to 7 days.
Store pistachio rhubarb tarts covered or uncovered refrigerated for up to 5 days. After 1 day the tart shells get a little soggy, and there may be some rhubarb leakage, but they will still taste great.

One of the pistachio rhubarb tarts on small white plate with other tarts on plates around

Troubleshooting Pistachio Rhubarb Tart Recipe:

My tart shell won’t come out of the tin! You didn’t spray it well enough! Release some of the edges with a knife, heat the tart tin over an open flame then gently bang out on the table.
My rhubarb compote is is really watery! You didn’t cook it long enough and evaporate that water out! You can either cook it down some more, or you can strain some of the liquid out.
My rhubarb compote is an ugly color! That’s okay; we cannot control the color nature. If I was not blessed with a lovely pink color for rhubarb then I add a few drops of red food coloring.
My meringue will not whip up! There may be some fat in the bowl! We’ve got to start over here. Clean the bowl and attachment/whisk thoroughly and give it a wipe with vinegar. Another issue could be the volume vs size of your stand mixer bowl. I have a 6 qt, pull up Kitchenaid mixer which needs larger quantities of meringue to whip up fully. For this, either increase the amount of meringue (I would double just to be safe) or hold the bowl higher to allow the whip attachment to hit everywhere.

Something else going wrong? Reach out and we will troubleshoot together!