Step 1

In a large pot over medium heat, warm the oil.

Step 2

Add the onion to the oil and cook, while stirring, until soft, about 5 minutes.

Step 3

Add the garlic to the softened onion and cook until fragrant, about 1 minute.

Step 4

Stir the tomato paste and the red pepper flakes into the onion mixture.

Step 5

Add the tomatoes and the broth to the tomato paste mixture and bring to a simmer.

Step 6

Add the penne to the sauce mixture and cook until al dente, about 8-10 minutes.

Step 7

Add the chicken, the mozzarella, the parmesan, the parsley, the salt, and the pepper to the sauce mixture and cook until the cheese melts.

Step 8

Serve.