Grill the chicken breasts until fully cooked and lightly charred.
Set the grilled chicken aside and keep it warm while preparing the sauce.
Cut the red bell pepper into thin, even strips.
In a skillet over medium heat, melt the butter.
Add the finely diced onion and minced garlic.
Sauté until the onion becomes translucent and the garlic is fragrant.
Add the red bell pepper strips to the skillet.
Cook for approximately 5 minutes, or until the pepper strips are tender but still slightly crisp.
In a blender, combine the white wine or vermouth, softened cream cheese, and sour cream.
Blend until the mixture is smooth.
Add the cooked red pepper, onion, and garlic mixture to the blender.
Blend again until the sauce is smooth and creamy.
Stop and scrape down the sides of the blender as needed to ensure an even texture.
Pour the blended sauce back into the skillet.
Heat the sauce gently over low to medium-low heat until hot.
Do not boil the sauce, as boiling may affect the texture.
Place the grilled chicken breasts on serving plates.
Drizzle the creamy red pepper sauce over the chicken.
Garnish with freshly chopped parsley.
Serve warm.