In a large skillet over medium-high heat, heat olive oil and butter over medium heat. Add chopped onion. Cook for 2 minutes until lightly softened.
1 tbsp olive oil, 2 tbsp butter, 1 small yellow onion
Cook ground beef and minced garlic clove for 5-7 minutes until browned.
1 lb ground beef, 1 garlic clove, 1 pinch salt
Add the beef broth, water, and pasta. Bring everything to a rolling boil and cook until the pasta according to package instructions, about 10 minutes.
2 cups beef broth, 8 oz penne, 3/4 cup water
5 minutes into boiling the pasta, add the broccoli florets and frozen peas. Bring the sauce back up to a low simmer and cook everything until the vegetables are tender and the pasta is al dente. Add more broth if needed (note 1 below).
1 1/2 cups broccoli florets, 1 cup frozen peas
On a low simmer, add the cream, followed by parmesan cheese. Stir until the cheese has fully melted and the sauce is creamy. Season to taste (note 2 below).
1 cup heavy cream, 1 cup parmesan cheese, 1/4 pinch salt, 1/8 tsp ground black pepper
Serve immediately with chopped parsley.
1/4 cup parsley