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

I love polenta with a passion, I grew up with it, and when it comes to side dishes, I would rather eat polenta than pasta or rice.
But polenta should not only remain a side dish. This polenta al forno recipe or Italian polenta and spinach bake makes an incredibly delicious and filling main dish. You could also try the Polenta Mushroom Casserole (with Cheese); it’s one of my favorite cornmeal dishes ever!
Recipe ingredients
Polenta:
- Also known as cornmeal. There are three different types of cornmeal: fine, medium, or coarse. You can use either medium or coarse to make polenta al forno, but keep in mind that the cooking time is different.
- Medium cornmeal needs about 15 minutes, while the coarse type needs about 40-50 minutes. Always check the package’s instructions.
Spinach:
- I use 10.5 oz/ 300 g frozen spinach weighed before defrosting.
- Defrost the spinach well and squeeze it thoroughly to remove the excess water before adding it to the bechamel sauce.
Cheese:
- I used three sorts of cheese: mozzarella, fontina, and Parmesan.
- You can sub fontina with other kinds of cheese; I sometimes use Cheddar, Gouda, Gruyere, or Bergkäse (strong-tasting, good-melting German/Swiss/Austrian cheese great for such bakes).
Ingredients for the white sauce: butter, all-purpose flour, milk, nutmeg, salt, and pepper.
Step-by-step instructions
Start with defrosting the spinach and preheating the oven. Butter the baking dish generously.
Cook cornmeal:
- Heat the water, add the salt (1).
- Slowly add the cornmeal while whisking all the time (2).
- Stir: Once everything is incorporated, continue stirring or whisking shortly to ensure no lumps.
- Simmer: 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: about 15 minutes for medium cornmeal and 40-50 minutes for coarse cornmeal. When cooking polenta, always check the package instructions and follow those instructions no matter what the recipe tells you.
Spinach sauce:
- While the cornmeal cooks, make the sauce.
- Squeeze the spinach well to remove the excess water.
- Bechamel: Melt the butter in a medium saucepan (3). Sprinkle the flour on top and roast it gently, stirring continuously (4). It should get only very lightly golden (5). Slowly, start adding the milk while whisking constantly. Let bubble gently until the sauce thickens (6).
- Add the squeezed spinach and combine (7).
- Adjust the taste with nutmeg, salt, and pepper.
Assemble:
- Grate the cheese. Reserve 2 tablespoons of fontina and about ⅓ of the Parmesan for sprinkling on top.
- Layer the polenta spinach bake: ½ of the polenta + spinach sauce + grated cheese (except for the reserved amount) + ½ polenta + reserved cheese.
- Bake for 25-30 minutes until golden. Serve immediately.
Tips for making polenta
- Make sure to check the package’s instructions regarding the cooking time necessary for various types of cornmeal.
- Please don’t skimp on salt when making polenta; it really needs it!
- Before adding the cornmeal, don’t let the water come to a rolling boil. The water should be almost boiling but not quite. This way, you can ensure that the dish will have no clumps.
- Once you add the cornmeal, the mixture will start to bubble immediately. Using a large pot diminishes the risk of getting your hands burned if the mix bubbles too violently. To avoid that altogether, wear mittens and turn the heat down.
Recipe FAQ
Yes, 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.
Not for this dish.
Not if you use cheese made with animal rennet (for instance, Parmesan).
To make the polenta and spinach bake vegetarian, use vegetarian hard cheese.
Polenta al forno is best served immediately.
But leftovers keep well in an airtight container in the fridge.
Reheat in the oven or microwave.
The dish is not suitable for freezing.
What to serve with it?
- I make a salad most of the time. Try a green salad with Yogurt Dressing, Shopska Salad (without the feta), Cucumber Salad with Dill.
- You can also serve the dish with French-Style Green Beans or Green Beans with Garlic, roasted broccoli or Brussels sprouts, or other vegetable side dishes you like.
More polenta recipes
Italian Polenta and Spinach Bake (Polenta al forno)
Equipment
- Large pot for polenta
- Medium saucepan for spinach sauce
- Casserole dish (about 8x9 inches/ 20x23 cm)
Ingredients
Polenta:
- 1 ½ cup polenta 9 oz/ 250 g
- 4 ¼ cups water 34 fl.oz/ 1000 ml
- 1 ½ teaspoon fine sea salt or Kosher
Spinach sauce:
- 2 tablespoons butter
- 3 ½ tablespoons all-purpose flour
- 1 ⅓ cup milk 10 fl.oz/ 300 ml
- 10.5 oz frozen spinach 300 g, Notes 1,2
- a few gratings of nutmeg
- fine sea salt
Bake:
- 1 mozzarella ball 4.5 oz/ 125 g
- 3.5 oz fontina 100 g
- 2 oz Parmesan 60 g, Note 3
Instructions
Polenta
- Heat the water in a large pot until almost boiling (Note 4), add the salt.
- 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.
- 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.
Spinach sauce
- While the polenta cooks, make the sauce.
- The spinach should be defrosted. Squeeze it well to remove the excess water.
- Melt the butter in a medium saucepan.
- Sprinkle the flour on top and roast it gently, stirring continuously. It should get 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.
- Add the squeezed spinach and combine.
- Adjust the taste with nutmeg, salt, and pepper.
Assemble polenta al forno
- Preheat the oven to 400 degrees Fahrenheit/ 200 degrees Celsius. Butter the baking dish generously.
- Grate the cheese. Reserve 2 tablespoons of fontina and about ⅓ of the Parmesan for sprinkling on top.
- 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.
- Cover with the remaining polenta.
- Sprinkle with the remaining cheese.
- Bake for 25-30 minutes until golden. Serve immediately.
Notes
- Weigh the spinach before defrosting. Squeeze it well once defrosted.
- 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.
- To make the dish vegetarian, use vegetarian hard cheese.
- Heat the water in a large pot but don't let it come to a boil (it helps against the formation of lumps).
Jeannie says
Mozzarella is listed as an ingredient but not mentioned in the recipe steps. Seems it would be fine without it.
Adina says
Hi Jeannie. When I wrote "Grate the cheese" I meant all three sorts. You will reserve just a bit of fontina and Parmesan for the top and mix all the rest.