1. Heat a large nonstick skillet over medium heat. Cook bacon, stirring often, until crispy (8-10 minutes); transfer bacon to a paper-towel-lined plate, reserving 1 tablespoon bacon fat in skillet. Meanwhile, cook pasta according to package directions in salted water; reserve 1/2 cup pasta water.
2. While pasta cooks, heat skillet and reserved fat over medium heat; add leeks and cherry tomatoes. Cook, stirring, until leeks begin to soften (about 5 minutes). Add reserved pasta water; simmer, partially covered, until tomatoes have burst and leeks are tender (12-15 minutes). Toss pasta with leek mixture and bacon and arrange in 6 serving bowls.