Pour off all but a thin coating of the bacon fat from the pan. Add the oil to the bacon drippings in the skillet and heat over medium high. Add the garlic and cook, stirring, until lightly golden, about 1 minute. Add half the Brussels sprouts and cook until lightly browned on the underside, about 4 minutes. Remove from the pan and, first adding up to a tablespoon of oil if the pan seems dry, add the remaining Brussels sprouts, again cooking until lightly browned, about 4 minutes. Return the first set of Brussels sprouts to the pan (all are now in the pan together), add the chicken broth and cook, stirring occasionally, until the Brussels sprouts are crisp-tender, 10-12 minutes. Remove from heat and stir in chopped bacon. Add salt and pepper to taste.