Melt the butter in a large saucepan over medium heat.
Add the garlic, stir and saute for 1 minute.
Whisk in the flour and whisk for 1 minute to cook.
Add the broth and stir. Bring to a boil and let boil until thickened, 1-2 minutes, stirring often.
Stir in the peach preserves, chili sauce, chili paste, Worcestershire sauce and onion soup mix. Bring to a simmer, stirring often.
Add the meatballs to a 5 quart slow cooker on high heat.
Pour the sauce over the meatballs. Cover and heat for 3 hours, stirring gently every 30 minutes or so.