Saute the onions and peppers in 6 tablespoons butter in a large skillet or Dutch oven over high heat until soft, about 4 minutes. Add the garlic and cook 2 minutes.
Add the mushrooms, Essence and thyme and cook until the mushrooms release their liquid, about 6 minutes. Sprinkle with the flour and cook 2 minutes.
Add the wine and stock and cook until smooth and thick, about 2 minutes. Add the cream, bring to a boil, then simmer over medium until thick enough to coat a spoon, 15 to 20 minutes.
Preheat the oven to 375 degrees F. Cook the noodles in salted boiling water until al dente, about 10 minutes, and drain. Butter a 9 by 13-inch dish with the remaining butter.
Stir the noodles, tuna, parsley, salt, pepper and Parmesan into the sauce. Transfer to the dish and top with the chips.
Bake uncovered until bubbly and golden, about 30 minutes.