Wash then pat dry chicken thighs with a paper towel. Take out excess fat from chicken Slice chicken into strips. Season with salt and pepper to taste.
Place a 12-inch non-stick skillet over medium-high heat, then add oil. When oil sizzles, add chicken to the pan in a single layer and brown both sides ; about 3-4 minutes per side. You may do this in batches to avoid overcrowding the pan.
Remove chicken from the skillet and set aside.
Melt 1-2 tablespoons of butter over medium heat, add in mushroom ,onions, garlic, thyme and bay leaf. Cook stirring for about 3-5 minutes or until onions are softened and translucent. Sprinkle in flour and cook for another minute stirring frequently to avoid burns.
Turn the heat to low and whisk in the chicken broth slowly, deglazing the pan by scraping off all the bits on the sides and bottom of the pan. Bring the mixture to a boil and simmer for 3 to 5 minutes.
Once the mixture has thickened, stir in the Worcestershire sauce, paprika, Dijon mustard and sour cream. Stir until evenly combined and aromatic, about a minute. Adjust salt and pepper to taste.
Return chicken to the skillet including all the juice on the plate of chicken . simmer again for 2-3 minutes then take pan off heat.
Sprinkle Stroganoff with fresh chopped parsley and serve with pasta, mashed potatoes or rice.