Portions: 6 servings Calories: 419kcal |
This flavorful polenta casserole is a dish that is full of complex flavors and is perfect for a weekend lunch. With Mediterranean flavors and inspiration, this delicious vegan polenta and mushroom casserole will please vegans and carnivores alike.
By - Last revised . Original Nov 3, 2011.
Why I ❤️ it Recipe Ingredients Preparation

Polenta casserole.
Why I ❤️ it
I have to tell you that this is one of my all-time favorites; there are a lot of Mediterranean flavors to this, perfect for a late lunch on a lazy weekend (or, as we call it, "dunch"). Just add fresh salad, some freshly-baked bread (or just reheat it in the oven), and some white wine for an easy yet refined light, gluten-free dish.
Don't be afraid of the multiple steps. It looks more complicated than it really is, and remember, this is almost a one-dish meal, so there won't be much slaving over the stove. I, for one, will definitely be cooking this often.
Polenta casserole recipe
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Utensils and tools
- Large saucepan or Dutch oven
- Large skillet or pan
- Lasagna baking dish

Ingredients
For the filling
- 2 tablespoons olive oil
- 1 white onion (large), cut into tiny cubes
- 1½ pound Portobello mushrooms
- ½ pound sun-dried tomato, cut into ½"-pieces
- 1 teaspoon salt (or more, to taste)
- ¼ teaspoon freshly-cracked black pepper (or more, to taste)
- ⅓ cup basil, chopped
For the tomato sauce
- 4 tablespoons olive oil
- 2 garlic cloves, crushed
- 5 tomatoes (large), peeled, seeded, and chopped
- 1 teaspoon oregano powder
- 1 teaspoon salt (or more, to taste)
- ¼ teaspoon freshly-cracked black pepper (or more, to taste)
For the base
Preparation
Before starting, please make sure you have all the ingredients and utensils ready.
Step 1: Make the filling

Heat the oil over very low heat. Add the onion, cook, and stir until the onions become translucent. Stir in mushrooms and sun-dried tomatoes. Simmer covered until the mushrooms are tender.
Season with salt and pepper to taste. Remove from the heat and add the basil. Set aside
Step 2: Make the sauce

Heat olive oil over very low heat. Add garlic and cook and stir until it releases its aroma, do not let it burn. Stir in the tomatoes and simmer covered until they are very soft. Add the oregano and season with salt and pepper to taste.
Using a potato masher, mash the sauce over the heat until there are no big clumps. Set aside
Step 3: Cook the polenta

Mix polenta, 1½ cup of water, sweet corn, raisins, salt, and sugar in a deep pot. Cook over medium heat, stirring constantly.
When the polenta is cooked, and it starts lifting from the bottom, remove it from the heat.
Step 4: Assemble the casserole

Preheat oven to 350ºF [175ºC]. Grease the baking dish with olive oil.
Pour half of the polenta mixture and spread in an even layer. Top with the filling and smooth it out. Spread the remaining polenta mix in an even layer and smooth it out with a fork.
Step 5: Bake

Cook in the preheated oven and cook until the top is lightly golden-brown (15-20 minutes).
Step 6: Serving

Serve alongside the tomato sauce.
Top tips
- If you don't have peeled tomatoes, just make a superficial cross cut at the bottom of the tomatoes and dunk them in abundant boiling water. Remove from the water when the peel starts to come off and finish peeling.
- If the polenta is sticking to your spatula or fork just grease the spatula with olive oil, the polenta will slide right off.
- You can use ground cornmeal instead of polenta too, but the texture and consistency will be a bit different.

Serving suggestions
Serve with fresh, green salad, olives, and warm bread, or this lovely halloumi salad.
Variations
You can add two layers of mozzarella cheese to the casserole if you don't need the dish to be vegan. You can also sprinkle some grated parmesan cheese for extra flavor.
You can add some Italian sausage removed from the case to the mushrooms when you sautee them if you want to add meat to the casserole.
If you can have dairy in your diet, you may also love this spinach casserole (with mushroom and quinoa).
Nutritional information
Calories: 553kcal - Carbohydrates: 23g - Protein: 36g - Fat: 35g - Saturated Fat: 14g - Cholesterol: 116mg - Sodium: 1642mg - Potassium: 765mg - Fiber: 2g - Sugar: 13g - Vitamin A: 1030IU - Vitamin C: 9.1mg - Calcium: 587mg - Iron: 2.2mg
More casserole recipes
FAQs
What is polenta?
Polenta is a type of ground corn that is a traditional Italian ingredient. Polenta is slightly coarser than cornmeal.
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Vegan Mushroom and Polenta Casserole Recipe
Ingredients
For the filling
- 2 tablespoons olive oil
- 1 white onion (large), cut into very small cubes
- 1½ pound Portobello mushrooms
- ½ pound sun-dried tomato , cut into ½"-pieces
- 1 teaspoon salt (or more, to taste)
- ¼ teaspoon pepper (freshly-cracked, or ground), (or more, to taste)
- ⅓ cup basil , chopped
For the tomate sauce
- 4 tablespoons olive oil
- 2 garlic cloves , crushed
- 5 tomatoes (large), peeled, seeded and chopped
- 1 teaspoon oregano (fresh leaves)
- 1 teaspoon salt (or more, to taste)
- ¼ teaspoon black pepper (freshly-cracked, or ground), (or more, to taste)
For the base
- 2 cups of quick-cooking polenta
- 1 cup sweet corn (or 1 can)
- ⅓ cup raisins (optional)
- 1 teaspoon salt
- 1 tablespoon sugar (white, granulated)
- 2 tablespoons olive oil (to grease the baking pan)
Instructions
Step 1: Make the filling
- Heat the oil over very low heat. Add the onion, cook, and stir until the onions become translucent. Stir in mushrooms and sun-dried tomatoes. Simmer covered until the mushrooms are tender.Season with salt and pepper to taste. Remove from the heat and add the basil. Set aside
Step 2: Make the sauce
- Heat olive oil over very low heat. Add garlic and cook and stir until it releases its aroma, do not let it burn. Stir in the tomatoes and simmer covered until they are very soft. Add the oregano and season with salt and pepper to taste.Using a potato masher, mash the sauce over the heat until there are no big clumps. Set aside
Step 3: Cook the polenta
- Mix polenta, 1½ cup of water, sweet corn, raisins, salt, and sugar in a deep pot. Cook over medium heat, stirring constantly.When the polenta is cooked, and it starts lifting from the bottom, remove it from the heat.
Step 4: Assemble the casserole
- Preheat oven to 350ºF [175ºC]. Grease the baking dish with olive oil.Pour half of the polenta mixture and spread in an even layer. Top with the filling and smooth it out. Spread the remaining polenta mix in an even layer and smooth it out with a fork.
Step 5: Bake
- Cook in the preheated oven and cook until the top is lightly golden-brown (15-20 minutes).
Step 6: Serving
- Serve alongside the tomato sauce.
Cook's notes
Nutrition
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Por , publicado Nov 3, 2011 en Tia Clara







Is the ratio of Polenta to Water correct? I usually make it a 1:4 ratio. With close to a 1:1 ratio, the result is extremely course and not something that can be eaten -- even if you cook it for a long time.
It worked for me. Bear in mind that the vegetables release some water while baking.
Hi, I'm a new vegan and I'm loving your vegan recipes. Can you tell Me how long to leave this in the oven for?
About 20 mins, or until the top is light golden.
Hello Aunt Clara.
Is polenta the same thing as cornmeal?
I want to try this recipe.
They're close, but not the same. You can find polenta in the grain section of the supermarket (or ask).
Hi!! Hats off to you for this website and its contents! I was born in th US but my family is originally for DR, as well as my husband. I have to say the first recipe that I tried was Pasteles en hoja. To say the least compliments did not… Read more »
This looks delicious. I love that you have so many vegetarian recipes, and the others are adaptable!
I can't wait to try this recipe. My sister is a vegetarian so it will be great for her too. Thanks Aunt Clara!
This looks seriously scrumptious, with warmth and comfort factor. Great idea and beautifully executed!
I love this recipe, and look forward to trying my own variation!! Polenta is one of my favorites. I am coming to the DR next week (Sosua area) to explore the idea of living there. Where are you located?? One of the reasons we are leaving Florida (to either the… Read more »
I live in PuntaCana, and I really have no experience living in the Sosua area. I would suggest that you visit our friends at DR1.com and enquire there.