Saute onion and then garlic until tender. Add strawberries, salt, and pepper. Saute for 4 minutes. Add remaining ingredients. Stir and bring to a simmer until the sauce is thickened. Remove from heat and blend sauce until smooth.
Heat grill. Place wrapped tenderloin on the unlit side of the grill. Cook until 138 F. Move to the heated side of grill and baste with barbecue sauce. Grill 5 more minutes, turning and basting halfway.
Serve your perfect pork tenderloin by slicing and drizzling with the strawberry barbecue sauce.
Grill it over indirect heat and remove them as soon as their internal temperature reaches 140 degrees.
You do not need to wrap pork tenderloin in foil when grilling.