Pat the chicken strips dry and season with sea salt and ground pepper. Melt butter in a skillet over medium-high heat. Cook the chicken for about 8 minutes, until golden brown and fully cooked. Remove and set aside.

In the same skillet, reduce to medium heat and sauté the diced onion for about 3 minutes. Add garlic and cook for another minute.

Add chicken stock to deglaze the skillet. Stir in sliced roasted red peppers and simmer for 5 minutes to thicken.

Remove from heat and whisk in heavy cream and Parmesan cheese until combined. Return to low heat and stir until slightly thickened.

Stir in Italian seasoning and drained pepperoncini. Return chicken to the skillet and simmer for 2 minutes.