Heat oven to 350°F (180°C) and fold a 7 x 7 inch (15 x15 cm) brownie pan with parchment paper.
Prepare the vegetables. Wash both mushrooms and tomatoes, then cut them. If desired, you can add other veggies like sautéed spinach or sliced onion.
In a large mixing bowl, add rolled oats, cottage cheese, Parmesan cheese, pesto or olive oil and all seasonings. Give a good stir to combine.
Add the prepared vegetables to the bowl, then mix until evenly combined. Feel free to stir in any additional ingredient you'd like such as sliced olives or chopped walnuts.
Transfer the dough to the prepared baking pan and spread it out evenly.
Bake in hot oven for 15 to 20 minutes, or until the savory oatmeal is ready. Do not overcook it, or it may get hard.
Let cool for 5-10 minutes before slicing into bars. Serve these savory baked oats as part of your breakfasts, lunches or dinners.