In a large frying pan, heat 2 tablespoons of oil over medium-high heat. Add the turkey sausage and cook, stirring frequently and breaking up, until cooked through, about 5 minutes. Add the garlic and cook for 1 min. Remove the pan from the heat. Stir in the mascarpone cheese. Add the thyme, oregano, bread crumbs, half the Gorgonzola, 1/2 tsp salt and 1/2 tsp pepper. Stir until all ingredients are combined.
Brush the mushrooms on both sides with the remaining oil and season with salt and pepper. Griddle the mushrooms, stem side down, for 3 minutes. Turn the mushrooms over and griddle for 2 minutes until tender. Fill each mushroom with the sausage mixture and top with the remaining Gorgonzola. Return the mushrooms to the griddle and cook until the stuffing is warmed through and the Gorgonzola starts to melt, about 5 to 7 minutes.
* Cook's Note: The assembled mushrooms can also be placed on a baking sheet and cooked under a preheated grill until warmed through.