Preheat oven to 400°

Wash and de-stem mushrooms (reserve stems for later)

Small dice onion and mushroom stems. Mince garlic

In medium sauteed pan caramelize onions and garlic

Add chopped mushroom stems to cook onions. Cook until tender. Add salt and pepper

In separate bowl, mix together sausage, salt, pepper, oregano, basil, sage, panko, and parmesan

Add cooked onions to sausage mixture

In a 8×8 or 9×13 pan place mushroom tops

Scoop small amount of sausage mixture into each mushroom top

Top stuffed mushrooms with panko and parmesan cheese

Bake for 25 minutes or until internal temp reaches 165°