In a large pot over medium-high heat, melt 2 tablespoons of unsalted butter. Season the boneless skinless chicken breasts with salt and pepper, then add them to the pot. Sauté for about 6-7 minutes per side until golden brown and cooked through. Remove the chicken from the pot and let it rest.

In the same pot, reduce the heat to medium and add 1 tablespoon of olive oil along with a finely chopped yellow onion. Cook for about 3-4 minutes until the onion becomes translucent.

Stir in half of the diced Roma tomatoes and 3 minced garlic cloves, followed by 1 teaspoon of dried Italian seasoning and a pinch of crushed red pepper flakes. Cook for an additional 2-3 minutes.

Sprinkle 2 tablespoons of all-purpose flour over the mixture. Stir continuously for about 1-2 minutes to form a roux.

Gradually whisk in 2 cups of chicken broth and 1 cup of half-and-half. Bring to a gentle simmer over medium heat and stir for 3-4 minutes until the sauce begins to thicken.

Return the chicken to the pot and add 8 ounces of linguine pasta. Stir to combine and cover the pot to let it simmer for about 10-12 minutes until the pasta is al dente.

Finally, stir in the remaining diced tomatoes and ½ cup of grated Parmesan cheese, adjusting seasoning if needed. Mix until the cheese melts into the sauce.

Remove from heat and mix in ½ cup of ricotta cheese and chopped fresh basil. Serve warm with extra Parmesan on the side.