In a saucepan put the butter, saute minced garlic, follow him with agave syrup and let everything blended. Then you add the vinegar and soy broth. Be careful not to burn, you can heat about 20 minutes over low heat stirring to take a darker color.
Stir in the tomato paste, pepper and garlic powder and let it cook about 10 min until it becomes thicker try and in case add more salt with soy sauce, if you think is acid add more agave syrup and if you think it is so sweet you can put more vinegar and broth.
Already with the Salsa list, put the ribs in a baking dish (you can cut here or the end) cover them with sauce and bake for 10 minutes you can to 200 degrees or you can cook on the grill to take a smoky flavor.
Doing them with honey instead of sugar lowers the calories in the recipe but not mean they do not get fat.