Mix the whole wheat flour, oat flour, baking powder and cranberry powder.
Put 1 egg and olive oil in the middle. Knead and incorporate warm water (little by little) until it doesn’t stick to your hands. Roll out the dough on the countertop, with some flour so it doesn’t stick, until it reaches the desired thickness.
Put the dough in a buttered baking pan and put in the oven, preheated to 360°F. Bake for 10 minutes.
For the filling, first cook the spinach leaves, stemless, in a pot with boiling water for 5 minutes. Strain and add cold water to cut off the cooking. Once cool, mince.
Thinly slice the mushrooms and finely dice the onion.
Sauté the onion with a dash of olive oil in a pan, then add the mushrooms, sauté for 2 more minutes and add the minced spinach. Set aside.
Mix the eggs, ricotta, salt and pepper in a bowl. Incorporate the spinach mixture and add sliced strawberries and grated cheese. Mix well and add to the dough.
Bake for 15 minutes or until the quiche is totally set and slightly brown.