Italian Polenta and Spinach Bake (Polenta al forno)

4.78 from 9 votes

Polenta al forno is a delicious Italian polenta and spinach bake with lots of cheese. A simple polenta casserole, soft, flavorful, and comforting.

Prep Time40

Cook Time30

Course: Main Course

Cuisine: Italian

Diet: Vegetarian

Servings: servings

Calories: 361kcal

Author: Adina

Heat the water in a large pot until almost boiling (Note 4), and add the salt.
4 ¼ cups water / 1000 ml + 1 ½ teaspoon fine sea salt or Kosher
Slowly add the polenta while whisking all the time. Be careful when the polenta starts to bubble; if the bubbles are too big, you might get burned – so turn the heat down (and wear mittens) if that happens.
1 ½ cup polenta / 250 g
Cook: Once the polenta is incorporated, continue stirring or whisking shortly to ensure no lumps. Turn the heat down, cover the pot, but leave a crack open. Stir every 2-3 minutes or so with a wooden spoon, but there is no need to stir continuously.
Cooking time: Read the cooking instructions on the polenta packet to know how long the cornmeal needs to be cooked. I cook the polenta made with coarse cornmeal for 40 to 50 minutes and the polenta made with medium cornmeal for about 15 minutes.

While the polenta cooks, make the sauce.
The spinach should be defrosted. Squeeze it well to remove the excess water.
10.5 oz frozen spinach/ 300 g
Make bechamel sauce: Melt the butter in a medium saucepan. Sprinkle the flour on top and roast it gently, stirring continuously. It should become only very lightly golden. Slowly start adding the milk while whisking continuously to avoid the formation of clumps. Let bubble gently until the sauce thickens; 1-2 minutes should do it.
2 tablespoons butter + 3 ½ tablespoons all-purpose flour + 1 ⅓ cup milk / 300 ml
Add the squeezed spinach and combine. Adjust the taste with nutmeg, salt, and pepper.
a few gratings of nutmeg + fine sea salt

Preheat the oven to 400°F/ 200°C. Butter the baking dish generously.
Grate the cheese (fontina and Parmesan) and tear the mozzarella into small pieces. Reserve 2 tablespoons of fontina and about ⅓ of the Parmesan for sprinkling on top.
1 mozzarella ball + 3.5 oz fontina / 100 g + 2 oz Parmesan / 60 g
Assemble the bake: Transfer ½ of the cooked polenta to the baking dish. Cover with the spinach sauce. Sprinkle with the grated cheese (except for the reserved amount) and the mozzarella . Cover with the remaining polenta. Sprinkle with the remaining cheese.
Bake spinach and polenta bake for 25-30 minutes until golden. Serve immediately.

Weigh the spinach before defrosting. Squeeze it well once defrosted.
Fresh spinach: You can use about 1- 1.3 lb/ 500-600 g. Wash it thoroughly and add it to a large pan with shaking it dry. Let it wilt entirely in the pan, drain it to remove the excess water, and add it to the sauce.
Vegetarian version: To make the dish vegetarian, use vegetarian hard cheese.
Make polenta: Heat the water in a large pot, but don't let it come to a boil (it helps against the formation of lumps).