~1lb of sliced bacon (use more if the bacon is thick-sliced), cut into 1/2″ slices
5 lbs red potatoes, clean, remove eyes, and cut into 1″ pieces
2 yellow onions, quartered and cut to 1/4″ slices
1 bunch of mustard greens, cleaned and cut to 2″x1/2″ pieces
1/4 cup cider vinegar
Pre-heat the oven to 425F.
Fry the bacon in batches, set bacon aside to drain and reserve the fat after each batch.
Pour some of the bacon grease on the potatoes to barely coat, season with salt if the bacon is more smoky than salty, and roast the potatoes in a single layer until soft in the center and lightly browned on the edges, about 20 minutes. 5 pounds fits on 2 half-sheet pans (I did this in batches, and I recommend doing 2 pans at once).
Fry the onions in more of the bacon grease until soft and starting to brown. Set the onions aside.
Cook the mustard greens in bacon grease until tender. Test them when they look wilted, if they still aren’t actually tender, add a little water to help them soften, season with salt if necessary.
Put everything in a big mixing bowl, add a bunch of black pepper, a 1/4 cup of cider vinegar, and stir until mixed.