Bring a large pot of salted water to a boil. Wash and dry all produce. Trim and slice mushrooms into 1/4-inch-thick pieces. Halve, peel, and thinly slice shallot. Halve tomatoes. Pick a few parsley leaves from stems for garnish; finely chop the rest of the bunch.

Heat a large drizzle of olive oil in a large pan over medium-high heat. Add mushrooms and cook, stirring, until browned, 5-7 minutes. Add shallot, another drizzle of olive oil, and chili flakes to taste. Cook, stirring, until shallot is softened, 2-3 minutes.

Once water is boiling, add ravioli to pot. Reduce heat to low. Cook until tender and floating to the top, 3-4 minutes. Carefully reserve 1/2 cup pasta cooking water (1 cup for 4 servings), then drain.

Once shallot is softened, stir tomatoes into pan, then reduce heat to low. Stir in sour cream, stock concentrate, half the Parmesan, and 1/4 cup reserved pasta cooking water (1/3 cup for 4 servings). Season with salt, pepper, chopped parsley, and a pinch more chili flakes if desired.

Add ravioli to pan, increase heat to medium, and gently stir to coat ravioli in sauce. Cook until sauce thickens slightly, 1-2 minutes. TIP: If needed, add more reserved pasta cooking water to give sauce a creamy consistency.

Divide ravioli mixture between plates. Garnish with remaining Parmesan and reserved parsley leaves and serve.