Clean the mushrooms, remove the stems and with a knife cut off the top rims to expand the surface for the filling. Mince the stems and rims finely.
In a pan, drizzle some olive oil and cook the sausages with the minced garlic, the minced mushrooms, and the rosemary, breaking them as much as possible with a fork or a potato masher. When the sausage is fully cooked turn off the heat and set it aside.
Preheat the oven at 400°F (200°C).
On a sheet pan, layer with parchment paper and add the mushrooms bottom side up. Drizzle or brush them with olive oil, then turn them and season the inside part with salt and black pepper.
Finely chop the Provolone and add it to the sausage filling. With a spoon, add the filling in the mushrooms, pressing lightly.
Sprinkle the top with Parmigiano cheese, then bake in the preheated oven for 15-20 minutes until golden on top.
Notes
You can prepare the mushrooms in advance and store in an airtight container in the fridge until you’re ready to bake them.
You can store leftovers in the fridge for up to 5 days.