1 1/2 lbs pork tenderloin (halved lengthwise and cut into 16 cubes)
1 medium red onion (cut into 8 wedges)
1 granny smith apple (peeled and cut into 8 wedges)
1. Heat grill to medium-high.
2. In a large bowl, combine jam, vinegar, tomato paste, and 1 tbs oil. Season with salt and pepper. Set aside.
3. Assemble 4 long skewers, alternation 4 pork cubes with 2 onion wedges and 2 apple wedges on each. Roll skewers in remaining olive oil. Season with salt and pepper.
4. Lightly oil grates on grill. Cover and cook, turning occasionally (about 6-8 minutes). Baste skewers with some sauce and cook, turning and basting occasionally with more sauce until pork is no longer pink in center and has a nice glaze (about 4-8 minutes).