Preheat the oven to 375°F. Line a baking dish with parchment paper.
Cook onion and bell pepper in oil in a saucepan over medium-high heat until vegetables are tender, about 3 minutes. Add garlic and continue to cook for another minute. Set aside to slightly cool.
Combine cooked onion mixture with beef, bread crumbs, egg, cilantro, coconut water, pineapple juice, Worcestershire sauce, lime juice, jerk seasoning, salt, and black pepper in a large bowl. Use your hands to mix everything together until well combined. Pinch off a piece of meat mixture and form it into a bite-sized ball, then place it in the baking dish. Continue the process; you should have 20 to 22 meatballs. Bake until lightly browned and cooked through, about 35 minutes.
YIELD: 6 servings I PREP TIME: 20 min I COOK TIME: 35 min I TOTAL TIME: 55 min