Preheat oven to 325 degrees F.

Rinse sauerkraut briefly in a colander to remove excess salt.

Press sauerkraut to remove excess liquid and set aside.

Melt 3 tablespoons butter in a skillet over medium-low heat.

Add bacon and cook until fat is rendered, about 4 minutes.

Add onions and cook until soft but not browned, 8-10 minutes.

Transfer bacon-onion mixture to a roasting pan or Dutch oven.

Add drained sauerkraut and toss to combine.

Create a bouquet garni with thyme, bay leaves, peppercorns, juniper berries, and garlic using cheesecloth.

Place the bouquet garni in the baking dish.

Add ham hocks, chicken stock, and beer and stir to combine.

Cover and bake for 1.5 hours or until ham hocks are mostly tender.

Melt the remaining tablespoon of butter in a skillet over high heat.

Brown the sausages on both sides and set aside.

Brown the pork chops and set aside.

Remove casserole from the oven and place the sausages on top of the sauerkraut.

Add water if the liquid has reduced to less than 2/3.

Cover the casserole and return it to the oven.

Cook for about 30 minutes, or until the sausages are tender and heated through.

Add the pork chops and press them into the sauerkraut.

Cover and return to the oven and cook until pork chops are heated through and tender, about 30 minutes longer.

Remove the casserole from the oven and discard the bouquet garni.

Serve immediately, with each person receiving some of each of the sausages, part of a hock, part of a pork chop and some of the sauerkraut.

Pass the mustard at the table.