Preheat grill or grill pan to medium-high.
In a large pot, place all the potatoes and cover them with cold water. Bring up to a bubble over medium-high heat and cook until tender. Drain thoroughly the return them to the pot. Add the beef consommé and give them a quick stir.
While the potatoes are cooking, cook the bacon in a small skillet over medium heat until crispy. Remove to a paper towel-lined plate to drain. Cook the onion in the same skillet with the bacon drippings. If there's too much oil in the pan, drain off all but 1 tablespoon. Cook the onion until soft, about 3 minutes, then set aside.
Place the knockwurst on the grill and cook until heated through and brown on the outside, about 7-8 minutes.