Halve larger potatoes and leave small potatoes as is, cover with water, bring to a boil, season with salt and cook until tender, about 8 to 10 minutes.
Place sausages in a cast iron skillet, add 1/2-inch of water and a drizzle of oil. Bring to a boil, reduce heat to medium and let the sausages heat through as the water evaporates. Shake pan and let the casings crisp up until they burst, 3 to 4 minutes, and are golden brown. Remove from the heat and set aside.
While sausages and potatoes cook, cut cabbage half into half again and trim away the core with an angled cut. Shred the cabbage very thinly with your knife and reserve. Place the shredder blade in your food processor. Peel the carrots and trim the root end. Trim the celery, and peel and quarter the red onion lengthwise. Peel the apple and quarter lengthwise then cut away the core as you did the cabbage. Using the processor, shred the carrots, celery, onion and apple, through the feed tube, removing from bowl as necessary.
In a large skillet heat 2 tablespoons of olive oil over medium-high heat. Add cabbage and vegetable mixture and toss to combine. Season the mixture with bay leaf, grill seasoning or coarse salt and pepper, and caraway seeds. Saute 7 to 8 minutes, tossing frequently.
While cabbage cooks, put a medium skillet on the stove with a drizzle of olive oil and heat over medium-high heat. Add chopped bacon and render 2 to 3 minutes then stir in the yellow onion and cook for 5 minutes with the bacon to soften.
Add hard cider to cabbage mixture and reduce for 30 seconds. Stir in the mustard and turn off the heat. Discard the bay leaf.
When potatoes are cooked, drain and add to bacon and onion. Douse the pan with vinegar and sprinkle with sugar. Pour stock evenly over pan, add the parsley and some pepper and turn off the heat. Stir the potatoes 1 minute to form a starchy sauce and combine flavors.
Halve crispy sausages and serve on generous bed of cabbage, with the potatoes alongside.
Serve with hard cider or white Belgian ale with orange wedge.