Mix beef, breadcrumbs, egg, grated onion, salt, and pepper in a bowl until just combined.

Roll into 1-1.5 inch meatballs and place in the crockpot.

Whisk honey, sriracha, soy sauce, garlic, and water in a bowl.

Pour sauce over meatballs, stir gently to coat.

Cook on low for 3–4 hours or on high for 1.5–2 hours until meatballs reach 160°F.

Stir once before serving and skim excess fat if needed.