My mom used to make baked sausage and cheese stuffed mushroom recipe similar to this on very special occasions. I thought we were the luckiest kids ever when she was cooking sausage stuffed mushrooms.
Remove the stem from mushrooms, dice stems only, and set aside.
Lightly oil a small baking dish and add the whole mushrooms in a single tight layer, cavity facing up.
Bring a large pan on the stovetop to medium high heat, add a little oil to lightly cover the pan (~ 2 tsp) and add sausage, onions, and mushroom stems.
Break up sausage with back of spoon or fork and cook ~ 7-10 minutes or until cooked through.
Add garlic and cook 1-2 minutes or until fragrant.
Reduce heat to low and add bread crumbs, both cheeses, salt and pepper. Stir together and remove from heat when cheese is melted (1-2 minutes).
Spoon (or use your hands) a bit of the mixture into each mushroom.
Bake uncovered ~ 40-45 minutes or until stuffing is browned and crusty.
Add salt to taste and sprinkle with parsley. Happy Eating! Beckie
Notes
Don't have bread crumbs or want to buy them? Pulverize older bread in a food processor. We always save our old bread in the freezer for this reason.
The filling for the mushrooms can be made the day before, cooled, and then stuffed into the raw mushrooms before baking the entire dish the next day.
Other mushrooms that work: cremini or portobello. Other cheeses that work: feta, cheddar, gruyere, colby jack.