This is a case where the food doesn't look very pretty, but it's tasty, quick and easy to make, so thought it would be good to share with all of you busy people.
The polenta is made as previously instructed. The mushrooms go like that:
Slice them, saute them in some olive oil, add salt and parsley flakes, maybe some freshly crushed black pepper, and keep sauteing until they're cooked (takes about 5-10 minutes). Toward the end you can add some heavy cream for extra richness (highly recommended, even if I didn't here).
Pour the mushrooms on top the polenta and sprinkle with shaved Parmesan or Romano.