A delicious tart from Wade Murphy, executive head chef at The Lodge at Doonbeg in County Clare, Ireland, that is wonderful to serve in the spring when rhubarb is in season.
For the pastry:
Combine the flour, sugar, and baking soda in a bowl and stir well to combine. Add the butter and rub it into dry ingredients. Add the eggs and buttermilk and stir well. Divide the pastry in two, wrapping each half in plastic wrap, and then store the dough in the fridge for at least 1 hour to let it rest (the pastry will be quite sticky). Then preheat the oven to 345 degrees Fahrenheit/175 degrees Celsius.
For the compote:
Combine the cornstarch, sugar, vanilla, and orange zest and mix together until well combined. Add the rhubarb and mix.
Place the rhubarb mixture into a saucepan and bring to a boil. Cook the mixture over medium-high heat until the rhubarb is slightly tender and brightly colored, about 8-10 minutes. Strain the rhubarb from the syrup and set it aside.
Remove the pastry from the fridge and let it soften for about 5 minutes. On a lightly floured surface, roll out one half of the dough until it is about ½-inch/1-centimeter thick. Lightly butter an old 7-inch enamel or tin camping plate (make sure it's ovenproof; you can also use a small pie tin). Place the dough onto the buttered plate and fill it with the rhubarb mixture. Using the second piece of pastry, roll the dough until it’s about 2 centimeters thick and use it to cover the top of the tart.
With a fork, seal the edges of the tart and then brush it with an egg wash made with one beaten egg. Pierce a hole in the middle of the tart to let the steam escape. Sprinkle with granulated sugar and bake at for about 18-20 minutes, or until the edges are golden.
Serve warm with fresh cream or crème anglaise.