Whisk together the ketchup, mustard, brown sugar, relish and Worcestershire together in a bowl, set aside.
Set a pan on your stovetop and add thawed ground meat + 1 tbsp olive oil. Sprinkle in dehydrated onions (and diced bell pepper if desired) cook until meat has very little pink left. Then fold in sauce and cook on low for about 5 more minutes.
Taste and if you want it sweeter add a bit more sugar, tangier add more mustard.
Turn heat off and put lid on the pan to keep warm, get sauce to thicken further and meat to soak up flavors for at least 5 minutes.