For Sauce: Sauté mushrooms, onions, bell peppers and garlic in 1/4 cup oil over medium heat 5 minutes. Stir in stock, tomatoes and wine. Bring to a boil; reduce heat. Simmer 5 minutes; keep warm.
Cut veal tenderloins crosswise into 2½ ounce slices. Pound slices to ¼-inch thickness. Refrigerate until needed.
Dredge 3 veal slices lightly in flour. Cook in 1 tsp. oil over medium-high heat to medium doneness, turning once. Season with salt and pepper. Plate veal topped with ½ cup Sauce. Garnish with olives.