Simmer the vinegar, raisins, dates and honey in a small saucepan over med heat until the raisins are soft, 2-3 min. Allow to cool to room temperature. Place the vinegar mixture in a blender, add the cheese and and puree until smooth. Add the mint leaves and pulse until minced. Slowly add the oil and continue blending until smooth.
Pour half of the mixture into a large bowl, add the lamb cubes and toss to coat. Cover with plastic wrap and refrigerate for at least 1 hour or overnight in the refrigerator. Put the remaining marmalade in a small bowl and season to taste with salt and pepper. Cover and refrigerate until reasy for use.
Preheat grill or broiler. Liberally sprinkle the lamb with salt and pepper. Place 2 lamb cubes on each skewer and grill or broil until lamb reaches desired doneness, about 1 minute per side for medium.
Serve with reserved marmalade on the side.