Combine flour, salt, pepper, 1 teaspoon sage and garlic powder in plastic bag. Add pork, several pieces at a time; shake to coat with flour mixture. Remove pork; pat off any excess flour. Reserve flour mixture in bag.
Heat 1-1/2 tablespoons oil in large skillet over medium-high heat. Add half the pork; cook 1 minute per side until browned. Remove to plate. Repeat with remaining pork.
Add remaining oil to skillet. Add mushrooms, thyme and remaining sage; cook 2 minutes, stirring. Add 3 tablespoons reserved flour mixture; cook 2 minutes, stirring. Stir in broth; cook, stirring, until smooth and slightly thickened, 2 minutes.
Return pork to sauce; simmer over low heat until cooked through, about 5 minutes.
Meanwhile, toast bread. Serve pork on toast with gravy. Makes 6 servings.