Saute the onions
and bell 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 for 2 minutes, stirring. Add the mushrooms, Essence, and thyme and cook, stirring occasionally, until the mushrooms are soft and have released their liquid, about 6 minutes. Sprinkle with the flour and cook, stirring, for 2 minutes. Add the wine and chicken stock and cook, stirring, until smooth and thick, about 2 minutes. Add the heavy cream
and bring to a boil. Reduce the heat to medium and simmer
, stirring occasionally, until the sauce is thick enough to coat the back of a spoon and very flavorful, 15 to 20 minutes.
Preheat the oven to 375 degrees F.
Meanwhile, bring a large pot of salted water to a boil and cook the egg noodles until al dente
, about 10 minutes. Drain
in a colander
and set aside. Butter a 9 by 13-inch casserole
or baking dish
with the remaining tablespoon of butter and set aside.
When the sauce
has thickened, add the noodles, tuna
, parsley, salt, black pepper, and Parmesan to the skillet and stir until thoroughly combined. Transfer to the prepared casserole and top with the potato chips. Bake uncovered until bubbly and golden brown, about 30 minutes. Serve immediately.