2 teaspoons extra-virgin olive oil
1/2 medium yellow onion, chopped
1 (8 oz.) package button mushrooms, sliced
2 cloves garlic, minced
1/2 teaspoon salt
1/4 teaspoon black pepper
1/4 teaspoon red pepper flakes (optional)
2 cups low-sodium vegetable broth
1 (14.5 oz.) can fire-roasted diced tomatoes
10 oz. thin spaghetti noodles (I use whole wheat)
3 cups fresh spinach or baby spinach
1/4 cup grated Parmesan cheese, plus extra for serving
For serving: 1/4 cup fresh chopped basil or parsley (optional)
INSTRUCTIONS
Heat olive oil in a medium pot over medium heat. Add onion and mushrooms and saute for 5-7 minutes, until tender and the liquid from the mushrooms has been mostly cooked off.
Add garlic and season with salt, pepper and red pepper flakes (if using) and saute another 30 seconds.
Increase heat to high then add canned tomatoes and vegetable broth. Bring to a boil.
Add spaghetti noodles and stir until they wilt and fit in the pot. Cover the pot, reduce heat to medium-low and cook for 5 minutes. (Your liquid should be at a low boil this whole time.)
Remove lid and add fresh spinach, a couple of handfuls at a time, stirring to get the spinach mixed in and wilted.
Remove from heat and let spaghetti sit, covered, for a few minutes
Stir in Parmesan cheese, taste and adjust seasonings.
Serve with fresh basil or parsley and extra Parmesan cheese, if desired.