Season the chicken breasts with salt and pepper on both sides.

Heat cooking oil in a large skillet over medium heat.

Add the chicken to the pan and sear for about 5-7 minutes until golden brown.

Flip the chicken and cook for another 5-7 minutes until cooked through (internal temperature of 165°F).

Transfer the chicken to a plate and cover with foil to keep warm.

In the same skillet, add chopped onion and minced garlic, sauté for about 3-5 minutes until translucent.

Stir in sliced pepperoncini, chicken broth, oregano, and basil, and bring to a simmer.

Let it bubble for 2-3 minutes to thicken.

Return the cooked chicken to the skillet and spoon the sauce over it, simmering together for 10-12 minutes.

Stir in heavy cream and Parmesan cheese until melted and smooth, cook an additional 2-3 minutes.

Serve hot over rice or mashed potatoes.