Mix the watermelon, onion and cabbage in a mixing bowl.

In another small bowl slowly mix the vinegar into the mustard and then pour the mixture over the watermelon/onion/cabbage mixture and toss together.

Grill the kielbasa until brown and crisp on the exterior but still juicy inside.

Remove from grill to a cutting board and cool for 5 minutes before cutting the kielbasa into bite sized pieces and skewer them with a pick.

Serve warm with the relish for scooping with the kielbasa.

Source:

Watermelon.org