Heat oil in large skillet over medium heat. Add onion and 2 minced garlic cloves; cook and stir about 5 minutes or until onion is tender. Remove from pan. Add ground beef; cook and stir 3 to 5 minutes or until browned. Drain. Stir in onion mixture and remaining filling ingredients. Season to taste with salt, if desired. Heat oven to 375 degrees. Separate one can of dough into 4 rectangles; firmly press perforations to seal. (Keep remaining can refrigerated until ready to use.) Cut rectangles in half crosswise to form 8 squares. Spoon heaping tablespoonful of filling in center of each square. Fold one corner of dough over filling to form a triangular packet; firmly press edges to seal. Repeat with remaining can of dough and filling. Place on two ungreased cookie sheets. If desired, sprinkle triangles with cumin. Bake on middle oven racks at 375 degrees for 10 to 15 minutes or until golden brown, switching positions of sheets halfway through baking. Meanwhile, in small bowl combine all sauce ingredients; mix well. Serve warm sandwiches with dipping sauce. (1/2 cup sauce)