Wash the asparagus under cold water. Remove the tough bottoms sections of the spears and discard. Cut off the tips and set aside. Cut the remaining sections into bite-sized pieces. Steam (or boil) the chopped portions for about 3 minutes or until tender. (After 2 minutes, add the tips, as they will soften more quickly.) If using fresh peas, add at the beginning. Remove from heat.
Heat the oil in a large skillet over medium heat, and add the onion. When translucent add the asparagus and peas. Cover with wine and cook together for about 2 minutes. Add salt and pepper to taste.
Meanwhile, bring a large pot of salted water to a boil. Cook the pasta until al dente, drain it, retaining some of the cooking water. Add the pasta to the skillet with the asparagus and peas and mix thoroughly. Add some of the retained cooking water if it seems dry.