Possibly my favourite application for rhubarb. Almost any tart fruit can be used, but the sour flavour of rhubarb marries beautifully with the nutty character of the brown butter.
Every time I brown butter I ask myself why I don’t do it more often. It’s quick, more or less foolproof, and one of the great, complex flavours of the kitchen. Simply put butter in a heavy pot over medium high heat, then remove once the moisture has boiled off and the milk solids have browned. If you need more guidance, you can think of browning butter like making syrup: as more and more water evaporates, the boiling point of the liquid rises. Use a candy thermometer and pull the brown butter off the heat once it reaches 130°C.
While the filling for this tart is dead simple, blind baking tart shells is a bit finicky, so this is something I make maybe once a year. I use this standard tart dough recipe and blind baking procedure.
Fresh rhubarb is preferred to frozen, which looses a good deal of its moisture and flavour during thawing. If using frozen rhubarb, thaw and strain off excess moisture to avoid diluting the filling.
Rhubarb Brown Butter Tart
Master Ratio – 1:2:2:3 flour, butter, egg, sugar
- 6 oz eggs (3 eggs)
- 9 oz granulated sugar
- 1 tsp kosher salt
- 1 tsp vanilla extract
- 3 oz all-purpose flour, sifted
- 6 oz unsalted butter
- 6 oz chopped rhubarb
- 1 French tart shell, par-baked to 3/4 doneness (recipe and procedure here)
- Whisk together the eggs, sugar, salt, and vanilla until smooth and pale. Add the flour and beat until well mixed.
- Heat the butter over medium-high heat in a small stainless steel pot until brown and nutty.
- Slowly pour the hot brown butter into the egg mixture while whisking.
- Distribute rhubarb evenly around the par-baked tart shell and pour butter mixture over top.
- Bake at 350°F until a crust forms and the filling is set underneath, about 40 minutes. (Don’t overbake or the brown butter will separate from the filling, giving it a greasy, grainy texture…) Cool to room temperature before cutting. Dust with confectioner’s sugar.