Beer-Simmered Bratwurst with Grilled Onions and Red Sauerkraut

There is nothing in this recipe which could possibly screw it up. Good bratwurst. Beer. Onions. Sauerkraut. Some sweet mustard we got from some German friends of ours. I won't say anything else about it other than:

It works.

SAUERKRAUT
2 cups red wine vinegar
1 cup water
¼ cup sugar
1 large head red cabbage, cored and thinly shredded
2 cloves garlic, thinly sliced
1 teaspoon whole mustard seeds
salt and freshly ground black pepper

BRATWURST
3 large onions, thinly sliced
3 lbs. precooked bratwurst, pricked with a fork
6 bottles dark beer
2 cups water
1 teaspoon coriander seeds
1 teaspoon caraway seeds
1 teaspoon mustard seeds
1" piece fresh ginger, peeled and chopped
hot dog buns
mustards, for serving

SAUERKRAUT
Combine the vinegar, water, and sugar in a large saucepan (not aluminum or castiron), bring to a boil, reduce the heat, and simmer until the sugar has dissolved. Add the remaining ingredients and simmer until the cabbage is soft, about 20 minutes. Season to taste with salt and pepper. (The sauerkraut can be made up to 2 days in advance, cooled, covered, and kept refrigerated. Bring to room temperature and drain before serving.)

BRATWURST
Arrange the onion slices on the bottom of a medium stockpot. Place the bratwurst on top and add the beer, water, coriander, caraway, mustard seeds, and ginger. Bring to a simmer and cook for about 10 minutes. Remove from the heat and set aside for at least 10 minutes and up to 1 hour.

When ready to serve, heat your grill to high.

Lift the sausages out of the pot. Remove the onions with a slotted spoon and place in a serving bowl. Discard the remaining liquid and aromatics.

Grill the sausages until crisp and golden brown on all sides, about 10 minutes total. If you like, grill the buns until lightly toasted. Serve the bratwurst on the buns with sauerkraut, onions, and mustard.