Preheat oven to 350°F.
Preheat a large skillet over medium-high heat and cook bacon until it’s crispy and golden brown. Once the bacon is done, remove it to a paper towel-lined patter to drain.
In a medium-size skillet, sauté the onion, celery, and carrot over medium-high heat with 2 tablespoons EVOO and 2 tablespoons butter until veggies soften, a couple of minutes. Set aside while you prepare the mushroom paté.
For the mushroom paté: Sauté chopped onion until tender. Add the garlic, and cook for two minutes. Add mushrooms and cook until they start to brown. Put mushroom, onion, and garlic mixture in a food processor with parmesan, ricotta, rosemary, and thyme.