"I was looking for a new way to use leeks other than in soup and I came up with this recipe. Another variation would be to leave the chicken whole and spoon leek cream sauce over baked or grilled chicken but that would add to cooking time."
Heat oil and vinegar in a skillet over medium-high heat. Add chicken; cook until white on all sides, about 5 minutes. Transfer chicken to a plate.
Stir leeks into the skillet; cook for 1 minute. Pour in wine; simmer until reduced by half, about 2 minutes. Add half-and-half, Parmesan cheese, salt, and garlic pepper; simmer until flavors combine, about 2 minutes.
Return chicken to the skillet and stir until heated through and coated with sauce, about 3 minutes. Season with salt and pepper.