Serve this healthy main dish from the grill for your next backyard cookout. The onion and sweet pepper for the relish are grilled with the lean pork tenderloin, giving the relish a roasted, slightly charred flavor.
1. Sprinkle pork with 1/4 teaspoon of the pepper, the garlic and 1 tablespoon of the rosemary. Cover and refrigerate 2 hours.
2. Prepare a charcoal grill with medium-hot coals or heat a gas grill to medium-high. Coat the grill rack with nonstick cooking spray for grilling. Brush onion and peppers with 2 teaspoons of the oil and grill, turning often, for 8 to 10 minutes, until lightly charred and crisp-tender. Cool vegetables slightly and chop.
3. Whisk vinegar, honey, remaining 1/4 teaspoon pepper, remaining 2 teaspoons rosemary and 1/2 teaspoon of the salt in a large bowl. Whisk in remaining 2 tablespoons olive oil. Add chopped onions and peppers. Set aside.
4. Sprinkle pork with remaining 1/2 teaspoon salt and grill, turning often, 20 to 25 minutes or until internal temperature registers 160 degrees F on an instant-read thermometer. Let stand 10 minutes before slicing. Serve pork with relish.