Add your onion to flat pan with some water. Cover and let it boil for a few minutes. Add the rest of the vegetables and cover.
2
Check that you always have some water in the pan - but just to keep the veggies from burning - don't drown your veggies.
3
Boil water with salt for the pasta. When boiling add your pasta and set the timer. Keep checking your veggies - add some salt and after about 10mins the asparagus should be soft. If not, add 5minutes.
4
Drain pasta, mix together, add some black pepper and serve. I didn't use olive oil, but you sure can add some at the end.