Preparation

Finely chop the parsley. Scrape the parsley into a pile on a cutting board. Using a handheld rasp-style grater, grate the small garlic clove and then the zest of the lemon over the parsley. (Put the lemon aside for later; you’ll need a few squeezes of the juice when you serve the pasta.) Finely chop together the parsley, garlic, and lemon zest. Scrape the mixture into a small bowl, add a pinch of salt and a few grinds of pepper, and stir to mix. Set the gremolata aside.

Bring a large pot of well-salted water to a boil. Meanwhile, place the bacon in a large cast-iron or nonstick skillet and cook over medium heat, stirring occasionally, until crisp, about 10 minutes. Using a slotted spoon, transfer the bacon to a paper-towel-lined plate. Pour the bacon fat into a small bowl and set aside. Return the skillet to the burner; do not wipe it out.

Cook the pasta for 1 minute less than package directions  for al dente. Reserve 1 cup of the cooking water, drain, and then  immediately rinse the pasta under cool water. Set aside.

Divide the arugula evenly among four serving dishes.

Heat 2 Tbs. of the bacon fat and the oil in the skillet over medium-high heat. Add the tomatoes, 1/4 tsp. salt, and 1/4 tsp. pepper. Cook, scraping the pan to loosen the browned bits, until the tomatoes are almost tender, about 5 minutes. Stir in one-third of the cooked bacon and the minced garlic. Add the pasta and 1/2 cup of the cooking water. Stir gently but thoroughly to combine everything in the skillet, adding more cooking water if needed. Remove from the heat.

Spoon equal portions of the pasta over the arugula on each plate and gently fold together. Add a generous pinch of the gremolata and a squeeze of lemon juice. Top with the remaining bacon. Serve with the remaining gremolata.