Heart Healthy Meatball Sliders

Ingredients

• 1/4 cup finely crushed panko bread crumbs
• 1 Tbsp chopped fresh flat-leaf parsley
• 1 large egg, lightly beaten
• 1 1/2 tsp olive oil
• 1 Tbsp ketchup
• 2 Tbsp grated Parmesan cheese
• 1/4 tsp onion powder
• 1 garlic clove, minced
• 1/8 tsp salt
• 1/4 tsp black pepper
• 8 oz 95% lean ground beef
• 12 whole wheat dinner rolls (2 1/2-inch diameter), halved
• Shredded Parmesan cheese, for serving (optional)
• Low sodium marinara sauce, for serving (optional)