In a shallow dish, mix together the flour, salt, and pepper.

Pat the chicken breasts dry with paper towels.

Dredge each chicken breast in the seasoned flour mixture, shaking off any excess.

In a sauté pan, heat the butter and vegetable oil over medium heat.

Add the chicken breasts to the pan and cook for 2 1/2 minutes on each side, until golden brown.

Add the sliced mushrooms and chopped garlic to the pan.

Cook for an additional minute.

Add the chopped green onion to the pan and cook for another minute until the chicken is almost done.

Drain any excess fat from the pan and set aside.

Serve the chicken hot, optionally garnished with additional chopped green onions