Potato Tart With Thyme and Manchego

Olive oil cooking spray1 pound baking potatoes, peeled and thinly sliced 1/2 medium yellow onion, very thinly slicedKosher salt and freshly ground black pepper1 teaspoon dried thyme, divided2 cups fresh baby spinach leaves3 cups grated Manchego cheeseDiced green or red hot peppers (such as pickled jalapenos), to tasteHeat oven to 425 degrees. Lightly spray a metal or glass pie plate with olive oil.Arrange a single layer of potato slices over the bottom of the pie plate, edges slightly overlapping. Lightly spray the potatoes with olive oil. Place 1/2 the onions in a thin layer over the potatoes, then season with salt, pepper and thyme.Top the onions with 1 cup of spinach leaves, spread evenly, then sprinkle with 1 cup of cheese. Place a second layer of potatoes over the cheese, pressing them down gently with the palm of your hand. Spray the potatoes lightly with oil.Repeat the layering by topping the potatoes with remaining onions, seasonings, remaining spinach, 1 cup of cheese and a final layer of potatoes. Gently press down on the potatoes, spray with oil, then top with remaining cheese and sliced peppers. Bake for 40 minutes, or until edges are golden brown and potatoes are cooked through. Cut into wedges to serve.Serves four.