Pasta salad is always gives opportunity being creative because you can combine the ingredients whatever you have in refrigerator. Cook the pasta aldente first since prepare the dressing and topping. Mix the olive oil, mustard, lemon zest, peck of salt and pepper in a large bowl. Once the pasta is cooked admix with dressing and same size sliced spring onion, celery and pickles. Before serving add the sausage slices. If you prefer you can make sausage crumbs toasting the small pieces of smoked sausage. Hereby I used the sausage without toasting. Best to serve in room temperature or warm.