Heat vegetable oil in a large skillet at medium to medium-high heat. Roll chicken pieces in flour and place in the hot oil, turning as they turn golden, but don't let them turn brown! Remove the from the oil and set aside, covered.
Drain off the used cooking oil, BUT USING THE SAME PAN, sauté the onions in olive oil until golden.
Stir in the rest of the sliced vegetables and chopped garlic until well incorporated. Return the chicken to the pan and carefully add the cooking sherry. Keep it at a low boil until the liquid reduces by half.
After it has reduced, add the chicken broth and the marinara sauce. Roll the butter in flour and add to the sauce. Let liquid reduce again. At this stage you could take a bit of the liquid and coat the cooked spaghetti.
Divide the cooked pasta on two dinner plates (or one serving dish) and pour the saut?ed veggies, chicken and sauce over it.Makes 4 Source: