Heat the olive oil in a large skillet over medium heat.
Remove the casing from the Italian sausage and crumble it into the skillet. Cook, stirring frequently, until browned, about 5-7 minutes.
Add the sliced onion, red bell pepper, and minced garlic to the skillet. Sauté for an additional 3-4 minutes until the vegetables are tender.
Add the broccoli florets to the skillet, stirring to combine. Pour in a splash of water (about ¼ cup) to help steam the broccoli and cover the skillet with a lid. Cook for 5-6 minutes until the broccoli is bright green and tender.
Remove the lid, and add the red pepper flakes, salt, and pepper to taste. Sprinkle the grated Parmesan cheese over the top and stir to combine.
Cook for another 2 minutes until the cheese has melted and everything is heated through.
Remove from heat and garnish with fresh parsley before serving.
Notes
Feel free to adjust the spice level by choosing mild or spicy sausage and adding more or less red pepper flakes.
Keyword broccoli, one skillet, quick meal, sausage