Put the grapes in a medium bowl with vinegar, oil, garlic, sugar, 1 teaspoon of the fennel seeds, ¼ teaspoon of flaked salt, and plenty of pepper. Mix well and marinate for at least 1 hour.
Thread 5 or 6 grapes onto each skewer. Don’t throw away the marinade; you’ll need it when serving.
Place a grill pan over high heat. Once hot, add the grape skewers in batches and grill for 2 to 3 minutes, turning after 1½ minutes. Remove from the heat.
When ready to serve, tear the balls of burrata in half and place one-half on each plate. Lean 2 grape skewers on the cheese and drizzle 1½ teaspoon of the marinade over the cheese. Sprinkle with the remaining fennel seeds and garnish with a sprig of basil. Serve immediately. Enjoy!
