Cut 12 (1-inch-deep) slits in top and bottom of roast.
Stir together garlic, next 3 ingredients, and 1 Tbsp. vegetable oil to form a paste. Rub mixture into slits. Cover and chill at least 8 hours or up to 12 hours.
Let roast stand at room temperature 30 minutes.
Brown roast on all sides in remaining 2 Tbsp. hot oil in a heavy-duty roasting pan over medium-high heat 5 to 6 minutes.
Stir together tomato sauce and next 3 ingredients; pour over roast in roasting pan.
Bake, covered, at 325 for 1 hour and 35 minutes or until a meat thermometer inserted into thickest portion registers 13
Remove roast, reserving sauce in roasting pan. Keep roast warm.
Whisk together flour and beef broth until smooth; whisk into sauce mixture in pan. Cook mixture, whisking frequently, over medium heat 15 to 20 minutes or until thickened.