In a large mixing bowl, combine the ground beef (or turkey), breadcrumbs, grated Parmesan cheese, chopped green onions, egg, minced garlic, minced ginger, salt, and black pepper. Use your hands or a fork to mix the ingredients together until they are thoroughly combined.
Shape the mixture into small meatballs, approximately 1 inch in diameter, and place them on a clean plate or cutting board as you go.
In a separate bowl, whisk together the sweet chili sauce, diced bell peppers, soy sauce, and sesame oil until well blended.
Transfer the formed meatballs into the crockpot, spreading them out evenly. Pour the sweet chili sauce mixture over the meatballs, ensuring that each one is generously coated with the sauce.
Secure the lid on the crockpot and cook the meatballs on the low setting for 4 to 5 hours or on high for 2 to 3 hours, or until the meatballs are completely cooked through and tender.
After the cooking time is complete, gently stir the meatballs in the sauce to ensure they are well-coated, then let them sit for an additional 10 minutes. This step allows them to absorb the rich flavors of the sauce.
Serve the meatballs warm, garnished with a sprinkle of sesame seeds and a generous handful of freshly chopped cilantro for a burst of flavor and color.
Notes
For a spicier kick, add some red pepper flakes to the sauce.