Combine the marmalade, lemon juice, and salt and pepper in a zip bag.
Add the chicken, and let marinate for 1 hour (minimum).
When ready to cook, preheat the oven to 325 degrees.
Spread the sesame seeds out on a baking sheet.
Bake until the seeds become brown and fragrant, approximately 5 minutes. (If you've made extra, store in a covered jar at room temperature, and use in other recipes.)
Combine honey, mustard, and sesame seeds for dipping sauce; refrigerate until ready to serve.
Preheat the grill to medium temperature.
Put the marinated chicken on the skewers.
Grill for 4-6 minutes per side, or until chicken is cooked through. Don't overcook!
Serve with the dipping sauce.