Set aside 4 tablespoons of the marinara sauce
for the top of the lasagna
. In large casserole dish
, layer: 6 cups of polenta, 1/2 the spinach / sausage slices, 1/2 the peppers, 1/2 the marinara sauce, 1/2 the Parmesan, and 1/2 the mozzarella slices.
Repeat. Top with the remaining polenta
(it may not cover the top completely). Distribute the ricotta mixture over the top in small dollops. Drizzle
the reserved marinara sauce on top. At this point the finished lasagna can be wrapped and refrigerated for up to a day.
Preheat the oven to 375 degrees F.
Place the pan on a cookie
sheet (in case it bubbles over). Bake about 45 minutes to 1 hour, or until it is bubbling and hot throughout. Remove from the oven and allow it to rest for several minutes before serving.