Rotate mushrooms in midway for an even cook. Mushrooms should be crispy, not hard.
Sauce:
Heat oil in a saucepan over medium heat.
Add onion, carrot, and garlic, cook for 7-10 minutes until vegetables are soft.
Add tomato paste and cook until it begins to caramelize.
Sprinkle flour in while continuously stirring and cook for an additional 3 minutes.
Add crushed tomatoes, broth, sun-dried tomatoes, basil, red pepper, and bring to a boil, then cover, and reduce to a simmer for 10 minutes. Allow the flavors to combine by simmering for 25-30 minutes.