In a medium pot, combine the beer, onions, ginger, and whole seeds. Bring to a simmer over medium heat.
Pierce the bratwursts all over with a fork and then gently slide them into the beer. Cover the pot, turn off the heat, and let the bratwursts cook for 15 minutes.
While the brats cook, prepare your grill for high heat direct grilling.
While your grill preheats, prepare your braised cabbage. Heat the olive oil in a large saute pan over medium heat. Dump in the shredded cabbage and toss to coat in the oil. Season with the salt and pepper.
Strain 1/2 cup of the beer braising liquid and add it to the cabbage. Cook about 10 minutes until softened and stir in the honey and vinegar. Transfer to a bowl and set aside.
Remove the bratwursts from the braising liquid and head out to the hot grill. Grill the sausages for about 2-3 minutes per side until the casings are crisp and browned.
Split the bratwurst buns and grill cut side down for about 30 seconds, until they are nice and toasty.
Slather each bun with some of the whole grain mustard, top with a crispy brat, and a pile of the braised red cabbage. Eat and enjoy!