Boil the potatoes and carrot. Set them aside to cool, then peel and dice.
Dice the sausage, shred the sweet pepper, chop the onion, and drain the tinned green peas.
Combine all the ingredients, dress with sour cream, 1/4 tsp of mustard, salt, and pepper.
Also, you might want to drizzle the salad with table or balsamic vinegar. It will add a slightly sour taste to the salad.