Chicken with spinach and mushrooms in a creamy parmesan sauce

Ingredients:
4 boneless, skinless chicken breasts
Salt and pepper to taste
2 tablespoons of olive oil
1 small onion, chopped
3 cloves of minced garlic
2 cups sliced ​​mushrooms
2 cups fresh spinach
1 cup heavy cream
1/2 cup chicken broth
1/2 cup grated parmesan
1 teaspoon Italian seasoning
1/4 teaspoon red chili pepper flakes (optional)