Heat olive oil in a Dutch oven over medium heat. Add shallots. Cook until they are softened, about one minute.
Add the sliced mushrooms and a large pinch of salt. Cook, stirring often, until the mushrooms are soft and most liquid has evaporated.
Add tomato paste and stir well.
Set aside 2 tbsp parsley for garnish.
Add garlic, red pepper flakes (if using), parsley, thyme, oregano and rosemary.
Stir until combined. Add red wine, stock and vinegar. Stir and scrape the bottom of any bits. Bring to a light boil, lower the heat and simmer, uncovered, for 15 minutes, stirring periodically. The mixture should be fairly thick.
Taste and adjust seasoning with salt and pepper if needed.
Serve over creamy polenta. Garnish with parsley and a few shavings of Parmesan (omit Parmesan for vegans).