I liked to cut up a bunch of onions and bellpeppers once a week so that when I make eggs in the morning I just need to put a scoop in the pan and add the eggs once they are cooked. This has been going well, but I want some more variety by adding sausage and potatoes to the mix as well. For the sausage I plan to precook it and mix it in with the veggies. However, I'm not sure what to do for the potatoes as they take longer to cook.  Should I simply chop and microwave them and add them? Or would I need to fry them a bit in the pan first so they will cook a bit in advanced? 
When I've done this sort of thing, as I like to have my potatoes with some crunchy brown exterior, I would do the following:   Bake a bunch of potatoes. Wrap them individually in aluminum foil, and stash them in the fridge.   On the morning of:   Start heating the pan, with some oil in it. Cut the potato into slabs Place the potatoes in the pan, and season the top. Go take a shower.  (I started the water before I came to the kitchen) Flip the potatoes, add the other vegetables, and some more seasoning Go get dressed Come back, flip the vegetables over (I left the onions in slabs of rings) Go and shave. Use my spatula to cut everything into bite-sized pieces. Crack eggs into pan, scramble & season Finish cooking the eggs & plate.   In your case, I don't know if I would mix the sausage in with the vegetables, as from the sounds of things the vegetables will still be raw.  You would have issues with trying to make sure that everything is cooked through to the degree you want ... whereas keeping them separate means you can add one a minute or two before the other.  