Begin by bringing a large pot of salted water to a rolling boil over high heat. Add the penne pasta and cook according to package instructions until al dente, about 10–12 minutes. Just 2 minutes before the pasta is done, toss in the broccoli florets, allowing them to brighten and soften. Drain everything together and set aside.

In a large skillet, heat the olive oil over medium heat until shimmering. Add the minced garlic and sauté for about 30 seconds, stirring frequently until fragrant and golden.

Sprinkle the flour over the sautéed garlic, whisking continuously for about 1 minute to form a roux. Gradually pour in the vegetable broth and heavy cream while stirring, ensuring there are no lumps. Bring the mixture to a gentle simmer and cook for 4-5 minutes, until it thickens.

Remove the skillet from the heat and stir in the grated Parmesan cheese, allowing it to melt. Season with salt, black pepper, and crushed red pepper flakes if desired.

Add the drained penne pasta and broccoli florets to the sauce in the skillet. Carefully toss everything together until well coated.

Stir in the fresh lemon juice and chopped basil for a burst of brightness. Mix well until fully incorporated.

Transfer your creamy broccoli pasta to a serving dish and serve immediately.