Bring large pot of salted water to boil. Stir in linguini and cook according to package directions, about 9 minutes. During last 4 minutes, add peas. Drain in colander, reserving ½ cup pasta liquid. Place pasta and peas in pot with reserved cooking liquid.
Meanwhile, heat 1½ tablespoons oil in large skillet over medium heat. Add minced garlic, bell peppers, leeks and pepper flakes. Cook 6 minutes, or until vegetables are tender, stirring occasionally.
Add vegetable mixture to pasta pot, along with lemon juice, lemon rind, salt and half of the mint. Toss to combine. Drizzle with remaining oil. Top with remaining mint and Serrano ham, if using.