Bring a large pot of salted water to a boil and cook pasta according to package directions. Meanwhile, in a large deep-sided skillet, cook bacon over medium heat until fat starts to render and bacon begins to brown. Add leeks and cook until softened. Set aside.
Drain pasta, reserving the cooking water. Set pasta aside. Place cooking water back on stove to simmer. Add peas to simmering water and blanch until tender-crisp, about 2 min. Drain peas, reserve 1/2 cup (125 mL) cooking water and run peas under cold water to stop cooking.
Add cooked pasta to skillet with bacon and leeks. With heat on low, stir in reserved cooking water, 1 tbsp (15 mL) at a time, to desired consistency. Stir well. With heat off, stir in peas, parsley, salt and pepper. Toss well.