Prepare Ingredients: Cut the broccoli florets into small, bite-sized pieces and measure out all remaining ingredients. Having everything prepped and ready will make the cooking process smooth and efficient, as this recipe moves quickly once you start cooking.
Create the Base: In a large skillet or pot over medium heat, melt the butter completely. Add the minced garlic and cook for 1 minute until fragrant but not browned. Then pour in the chicken broth and half and half, followed by all seasonings (onion powder, thyme, salt, oregano, and parsley), stirring to combine.
Cook the Pasta: Once the liquid comes to a boil, add the pasta shells to the pot. Partially cover the pot and cook according to the package instructions, stirring occasionally to prevent sticking. When 6 minutes of cooking time remain, add the broccoli florets to the pot, allowing them to cook alongside the pasta until tender-crisp.
Finish the Sauce: After the pasta and broccoli are cooked to your desired tenderness, remove the pot from heat. Add the lemon juice and gently stir in the grated Parmesan cheese until melted and incorporated. Allow the pasta to sit for 2-3 minutes before serving, as the sauce will continue to thicken upon standing.