If using wooden skewers, soak them in water for at least 30 minutes prior to using.
Heat grill to medium-high heat (400ºF).
In a small bowl, combine apricot preserves, lemon juice, mustard, rosemary, red pepper flakes, and 1 tablespoon olive oil. Set aside half of the glaze to use as dipping sauce.
½ cup apricot preserves, ¼ cup lemon juice, 3 tablespoons Dijon mustard, 1 teaspoon finely chopped fresh rosemary, ¼ teaspoon red pepper flakes
Thread the pork, apples, and onions onto the skewers and brush with 1 tablespoon olive oil; sprinkle with salt and pepper.
½ teaspoon kosher salt, ¼ teaspoon coarse ground black pepper, 1 ½ pounds pork tenderloin, cut into 1-inch chunks, ½ red onion, cut into 1-inch chunks, 1 large apple, peel left on, cored and cut into 1-inch chunks
Grill for 10 to 12 minutes, turning once and brushing with glaze frequently, until cooked through (145ºF when checked with an instant read thermometer).
Serve kabobs with reserved glaze on the side.
Video
Notes
Apples: Suggested apple varieties: Granny Smith, HoneyCrisp, Jonathan, Empire, Pink Lady, Golden Delicious, or Mutsu (Crispin)
Oven: Broil the kabobs in your oven instead of grilling.
Chicken kebobs: Substitute boneless skinless chicken cut into 1-inch pieces, if desired.
Flavor variations: Instead of apricot preserves, try cherry, raspberry, or orange marmalade.