Mix all the ingredients together in a saucepan, excluding the peaches and simmer over medium heat for 15 to 20 minutes.
While the sauce is simmering, puree 2 cups of canned or fresh peaches. Once the sauce is cooked, add the pureed peaches to the sauce and stir together.
Preheat the grill to medium heat. Season the tilapia with house seasoning. Cook the fish on each side for 3 to 4 minutes. During the last few minutes of cooking, brush the fish with some barbecue sauce.
Once cooked and plated, ladle a nice spoonful of the Peach barbecue sauce on top of the fillets.