Prepare the Ingredients: Chop the garlic, onion, and broccoli. Set aside.
Sauté the Aromatics: Melt butter in a pan over medium heat. Add garlic and cook for 1 minute, or until fragrant. Add onion and cook for 5 minutes, or until soft and translucent. Stir in broccoli and cook for another 5 minutes.
Cook the Pasta: Cook Tortelloni according to package instructions. Reserve 1/2 cup pasta water before draining.
Make the Sauce: Add heavy cream to the broccoli mixture and simmer over medium heat. Stir in the reserved pasta water and Parmesan cheese until well combined.
Combine and Finish: Gently fold in the cooked Tortelloni. Reduce heat to low, cover, and cook for 5–7 minutes, or until the sauce thickens.
Serve: Remove the lid, gently stir, and serve immediately. Enjoy!