Heat olive in a large saute pan and add in the chicken thighs.

Season thighs with salt and pepper, as desired; cook thigh pieces 4-5 minutes, stirring to evenly cook.

Melt butter in a large stockpot.

To the stockpot add garlic, mushrooms, celery, onion and roasted red peppers; cook 4-5 minutes, stirring to combine.

Stir in the flour and cook until just lightly browned (about 2 minutes or so), being careful not to burn or scorch the flour.

Stir in the chicken stock and bay leaves; then add in the chicken; stirring well to combine all ingredients. Let soup simmer over medium-low heat for about 5 minutes.

Stir in the 2% milk and half-n-half and continue to cook over medium-low heat; season with additional pepper, if desired.

Make a slurry of the cornstarch and cold water, then gently stir into simmering soup; let soup continue to simmer 5-10 minutes, or until desired consistency. If soup becomes too thick, add more 2% milk over low heat.

Serve immediately with a parsley garnish, if desired. Immediately store leftovers in refrigerator when soup broth has cooled.