Preheat oven 350ºF.
Sprinkle the mushrooms with salt and pepper and bake for 20 minutes.
While that cooks, sauté the zucchini in a little bit of butter and set aside.
Then, sauté the bell peppers and set a side.
Once the mushrooms are ready, slide onto plates and top with spinach, zucchini and the red bell pepper.
Add some dill mayo and top with the feta cheese.