Step 1Simmer the vinegar, raisins, dates and honey in a small saucepan over medium heat until the raisins are soft, 2 to 3 minutes. Let cool to room temperature.
Step 2Puree this mixture, along with the pine nuts and cheese, in a food processor until smooth. Add the mint leaves and pulse until minced. Slowly add the oil and continue blending until smooth. (Makes 1/2 cup.)
Step 3Toss the lamb cubes with half of the mint marmalade in a large bowl. Cover with plastic wrap and refrigerate for at least 1 hour and up to 12 hours. Put the remaining marmalade in a small serving bowl and season to taste with salt and pepper. Cover and refrigerate.
Step 4Heat the grill or broiler. Liberally sprinkle the lamb with salt and pepper. Place 2 lamb cubes on each wooden skewer and grill or broil until the lamb reaches the desired doneness, about 2 minutes per side for medium rare.
Step 5Serve with the reserved marmalade on the side.