In a saute pan over medium high heat, melt the margarine and add the minced shallot. You could also add a bit of garlic here, I'm just not a huge fan ;) Saute until slightly translucent.
Steam the asparagus (or use a microwavable steamed asparagus).
Combine the broth and cornstarch, mixing well. Add to the pan and bring to a boil. Continue to cook until thickened. Stir constantly.
Stir in the cream, lemon juice, salt, pepper and red pepper.
Remove from the heat and add the peas. Cook for a minute or two and add the steamed asparagus.
Drain the pasta and add to the sauce. Stir gently to combine.