Preheat your oven to 350 degrees f. and line a large, rimmed baking sheet with parchment paper.
Clean your mushrooms, remove the stems, and pat dry. Arrange the mushrooms, on your prepared baking sheet as shown, very lightly brush with oil, then roast until tender, about 12-15 minutes, depending on their size. Once ready, allow to cool for a minute or two, then lightly pat dry again, with a paper towel.
Meanwhile, small dice your mushroom stems, shallots, bell pepper, celery, carrot, and garlic.
Melt the ghee in a large skillet over medium heat. Add in all your chopped veggies, fresh herbs, and sea salt & pepper to taste, then sauté, stirring often, for about 5 minutes.
Divide your sautéed veggie mixture among mushroom caps and sprinkle with shredded parmesan and a few extra herbs if desired.
You may place your stuffed mushrooms back in the oven for a minute or two, just to melt the cheese if desired.
Enjoy while hot, or at room temperature.