Melt butter in a medium saucepan over medium heat.  Add the onions and cook, stirring occasionally until translucent, about 5 minutes.  Stir in the garlic and Serrano pepper and cook, stirring, for 2 minutes.  Add the peaches and cook until softened, about 5 minutes.  Add the ketchup, bourbon, orange juice, lemon juice, and brown sugar and stir to combine.  Bring mixture to a simmer and cook for 30 minutes, or until thickened.

Remove from the heat and strain sauce through a wire mesh strainer set over a medium bowl, pressing to release all of the juices.  Discard the solids, cover the sauce, and cool slightly.

Preheat a grill to medium heat.

Season the salmon on all sides with ¾ teaspoon salt and ¼ teaspoon pepper.  Place the fish on the grill and cook for about 3 minutes then turn the fish 45 degrees and cook for an additional 3 minutes. Turn the fish over and cook for an additional 5 minutes or until cooked through. During the last few minutes of cooking, brush the fish with the reserved peach sauce.

Serve the salmon over Pecan Wild Rice with the remaining warm Peach-Bourbon Barbecue Sauce.