Combine ground beef and pepper in medium bowl, mixing lightly but thoroughly. Lightly shape beef mixture into four 1/2-inch thick oval patties. Heat oil in large nonstick skillet over medium heat until hot. Place patties in skillet; cook 10 to 12 minutes or until instant-read thermometer inserted horizontally into center registers 160°F, turning occasionally. Remove from skillet; keep warm.
Heat butter in same skillet. Add mushrooms and onions; cook and stir 3 to 4 minutes until tender. Dissolve cornstarch in broth. Add broth mixture to skillet; bring to a boil, stirring occasionally. Reduce heat; cook 3 to 4 minutes until thickened. Stir in Worcestershire and bouillon granules; cook 2 minutes.
Return patties to skillet; heat through. Serve Salisbury steaks with gravy and your favorite vegetables and mashed potatoes, if desired.
Nutrition information per serving: 241 Calories; 108 kcal Calories from fat; 12 g Total Fat; 5 g Saturated Fat; 5 g Monounsaturated Fat; 85 mg Cholesterol; 540 mg Sodium; 9 g Total Carbohydrate; 1 g Dietary Fiber; 25 g Protein; 3 mg Iron; 7.3 mg Niacin; 0.4 mg Vitamin B6; 2.2 mcg Vitamin B12; 6 mg Zinc; 23.8 mcg Selenium; 84 mg Choline;