Tarragon Streusel Topping
Make pie dough. Place flour, sugar, cornmeal, and salt in a food processor. Pulse to combine. Add chilled butter and pulse a few more times, until mixture has pea-sized chunks of butter. Drizzle in 2 to 3 tablespoons ice water and pulse until dough holds together when squeezed. Add another tablespoon water if needed. Form dough into a disk, cover with plastic wrap, and refrigerate for 30 minutes.
Make streusel topping. In the same food processor, add the flour, sugar, and tarragon. Pulse to combine. Add butter and pulse until crumbly. Pour into a small bowl and refrigerate until needed.
Preheat oven to 400°F. Combine plums and sugar in a large bowl. Set aside. Remove pie dough from refrigerator and roll out on a floured surface to fit an 11-by-7-inch rectangular tart pan or a 9-inch round tart pan. Place the dough gently into the tart pan and ease it into the corners, pressing with your fingers. Roll a rolling pin over the top edge of the pan to remove excess. Drain the plum/sugar mixture using a sieve and return mixture to bowl, discarding drained liquids. Add flour and salt and gently toss until plums are evenly coated.
Shingle plum slices into prepared pan. Scatter streusel topping on top. Place tart on rimmed baking sheet and bake for 40 to 45 minutes or until golden brown. Cool 30 minutes before serving.
Makes 6 to 8 servings
Photograph by Matthew Benson
Originally published in Organic Gardening magazine, June/July 2014