Preheat oven to 375 F.

Line a baking sheet with aluminum foil.

Lightly cook the onions in a pan then add the meat.

When it is starting to turn brown, add the garlic.

Once the meat looks evenly light brown, add the carrots celery, and salt and pepper.

Cook on medium/high until the meat has a nice dark brown color.

Add the rosemary and stir thoroughly.

Meanwhile, using a damp cloth, wipe each mushroom down.

Using a serrated grapefruit spoon if you have one (or a regular soup spoon if you don’t), hollow out the mushrooms.

Fill with the mushrooms with the ground beef, place on the baking sheet, and bake at 375 for about 10 minutes.

Let cool slightly then enjoy!