My mom encouraged me to make this tart because the picture in the book looked really delicious. I love Deborah Madison's recipes for their clean, simple flavors. This tart might seem like a lot of work, but it isn't really. If you make the tart shell ahead of time, the rest of the process will be a cinch. If I can make all the components in a few hours, so can you.
adapted from Vegetarian Suppers in Deborah Madison's Kitchen
1/2 cup + 2 Tbsp All purpose flour
1/2 cup whole wheat flour
3/8 tsp sea salt
5 tbsp butter
3 tbsp sour cream (I actually used some tart yogurt and it came out fine.)
Pulse the flours and salt in a food processor. Add the butter and pulse until it looks like fine crumbs. Add the sour cream and pulse again until combined. Add ice water 1/2-1 tbsp at a time until the mix barely comes together. You don't want it to be too wet or sticky.
Refrigerate the dough for 15-30 minutes. This seems short, but I had no problem at all with dough shrinkage. Roll the dough out to fit a 9 inch tart pan (about 1/4 inch thick) and fit it into the pan. Poke a few holes in the bottom with a fork. Freeze for 15-20 minutes, or until firm. Preheat your oven to 425. Pre-bake for 20-25 minutes until it just starts to color.
1/2 cup dried porcini mushrooms
1/2 cup dry white wine (...or water if you don't have any.)
1 large white onion, finely diced
1/2 lb sliced portobello mushrooms
1/2 lb white or cremini mushrooms, sliced
1 tsp tomato paste
1-2 Tbsp parsley, thyme, or marjoram (or any combo) chopped finely
2/3 cup half and half, cream, or mushroom stock (I used a combo of cream and stock.)
salt and pepper to taste.
Heat the dried mushrooms, wine, and 1/2 cup water in a small saucepan until boiling. Remove from heat and set aside for 30 minutes. Strain the mushrooms, reserving the liquid, and chop them into a rough dice.
Meanwhile, heat the oil in a large skillet. Saute the onion until it starts to color (about 5 minutes.) Add the portobello and cremini mushrooms and about a tsp of sea salt and turn the heat to high. Saute until they are browned but try not to overcook them. (5-10 minutes) Add half the herbs and tomato paste, and the porcini mushrooms. Add a few tablespoons of the soaking liquid- and add more a little at a time until the mushrooms are glazed and cooked.
Pour the hot filling into the prebaked tart shell. Mix together the egg and half and half and pour over the tart. Bake in the 425 oven for 25-30 minutes, until the custard is set. (Mine was done in about 20, but I didn't use all the custard.) Sprinkle the finished tart with the rest of the herbs, and brush the top with a little oil if you like.