Heat the oil in a large pot or Dutch oven over medium heat. Add the onion and cook until softened, 3-4 minutes. Stir in the garlic and cook until fragrant, about 30 seconds.

Add the mushrooms to the pot and stir well. Raise the heat to medium-high and cook for 8-10 minutes, or until the mushrooms release their juices and they evaporate; the mushrooms should be browned, with bits sticking to the bottom of the pot.

Next, deglaze the pot with wine. Pour the wine into the pot and use a wooden spoon to scrape off anything stuck to the bottom. Continue to cook on medium-high heat until the wine has almost completely evaporated, about 5 minutes.

Add the crushed tomatoes, tomato paste, basil, oregano, and pepper flakes; reduce heat to low, and simmer for about an hour, or until the sauce has thickened. If needed, add a teaspoon or two of sugar to cut the acidity and season with salt and pepper to taste.