Mushroom, Spinach and Cheddar Whole Wheat Tarts

Steps

1. Make the crust: in a large bowl, whisk together the whole wheat flour, the all-purpose flour and half of the salt to make the dry mix.
2. Rub the cold butter into the dry mix with your fingertips or a pastry cutter until it looks like coarse crumbs with some pea-size pieces.
3. Drizzle in the ice water a little at a time, tossing with a fork, until the dough holds together when squeezed.
4. Divide the dough in half, press each half into a flat disk, wrap and chill for 1 hour.
5. Roll each disk into a 12-inch round and fit into two 9-inch tart pans with removable bottoms; trim the edges, prick the bases with a fork and chill 15 minutes.
6. Preheat the oven to 400°F (200°C). Line each crust with parchment and pie weights and bake 15 minutes; remove the weights and parchment and bake 8 to 10 minutes more until dry and lightly golden. Lower the oven to 350°F (175°C).
7. While the crusts bake, make the filling: heat the olive oil in a large skillet over medium heat, add the onion and cook 10 minutes until soft and golden.
8. Add the mushrooms and thyme and cook 10 to 12 minutes, until the mushroom liquid has evaporated and they are browned.
9. Stir in the spinach and cook 2 minutes until wilted, then cool the vegetables for 10 minutes.
10. In a bowl, whisk the eggs, milk, the remaining half of the salt, the black pepper and the nutmeg until smooth to make the custard.
11. Scatter half of the cheddar over the two baked crusts, divided evenly, then spread the mushroom and spinach mixture over them, divided evenly.
12. Pour the custard evenly into both tarts and top with the remaining half of the cheddar.
13. Bake at 350°F (175°C) for 30 to 35 minutes, until the custard is set with a slight wobble in the center and reaches 160°F (71°C).
14. Cool the tarts on a rack for at least 30 minutes, then remove from the pans and cut each into 6 slices.