In a saucepan, combine the water, bratwurst, and onion slices. Bring to a boil over high heat.
Reduce heat and simmer 10 minutes. Internal temperature should reach at least 165 degrees.
While the brats are simmering prepare the slaw. Combine all remaining ingredientsin a medium mixing bowl. Stir to combine. Refrigerate until brats are completed.
Transfer brats to a hot grill to add some smoky flavor. Turn after 3 - 4 minutes to brown on both sides.
Serve immediately.
Serve the Grilled Bratwursts on a bun with mustard or your favorite condiments with the homemade Kale BBQ Slaw.