Use a zester to remove the rind from the lemon and then juice the lemon. Cook the pasta in salted boiling water following directions until almost al dente. Add the peas, snow peas and asparagus to the boiling pasta and cook for 1 minute or until bright green, drain well.
Heat oil in frying pan over high heat; add zucchini or zucchini flowers and cook, tossing, for 2 minutes or until tender, transfer to a bowl.
Add the garlic to the pan and cook 1 minute, then add mustard, cream, lemon juice and half the zest and bring to the boil. Cook for 2 minutes or until sauce thickens, add zucchini and pasta mixture and toss to combine.
Season with salt and pepper. Serve into individual bowls and top with remaining zest and parmesan. Serve immediately.
