Pat the chicken breasts dry and season both sides with salt, pepper, paprika, thyme, oregano, and cumin. Let rest for 10 minutes.

Melt 2 tablespoons of butter and olive oil in a skillet over medium-high heat. Add the seasoned chicken and cook for 6-7 minutes on each side until golden brown. Transfer to a plate.

In the same skillet, reduce heat to medium and add the remaining butter. Sauté the onion, red bell pepper, and yellow bell pepper for 5-7 minutes until softened. Add garlic and sauté for another 1-2 minutes.

Pour in heavy cream, stirring to combine. Add Dijon mustard if using, and season with salt and pepper. Let simmer for about 5 minutes until thickened.

Return the chicken to the skillet and simmer for an additional 2-3 minutes for the flavors to meld.

Remove from heat, garnish with parsley, and serve immediately.