Vegetarian Spinach and Mushroom Lasagna

INGREDIENTS

1 1/2 lb

cremini mushrooms, roughly chopped

1/2 lb

shiitake mushrooms, roughly chopped

Salt

generous cup of chopped onions

1/4 cup

olive oil plus more for keeping the noodles from sticking to each other

4 cloves

garlic, chopped (about 4 teaspoons)

1 6 ounce can

tomato paste

2 cups

tomato sauce

1 28 ounce can

crushed tomatoes (I recommend Muir Glen brand with added basil)

1 cup

water

1 tbsp

dried thyme

1/2 tsp

red pepper flakes

1 tbsp

sugar

boxes frozen chopped spinach, thawed, squeezed in clean towel of excess moisture

1 lb

lasagna noodles (16 to 20 noodles)

15-or-16-ounce container of ricotta cheese

1/4 cup

chopped fresh basil

1/4 lb

pecorino cheese (or Parmesan), grated (about 1 cup)

1 lb

shredded mozzarella cheese (about 4 cups)