Preheat the oven to 500°. Bring
a large pot of water to a boil, salt it, add the pasta and cook until
al dente. Drain, reserving 1 cup pasta cooking water.
While the pasta is working, in a large skillet, heat a drizzle of EVOO over medium-high heat. Add the bacon and cook until crisp at the edges, 3 to 5 minutes. Add the leeks and cook until softened, 3 minutes. Add the garlic and crushed red pepper and cook, stirring, for 1 minute. Stir in the tomato paste for 1 minute. Stir in the cream cheese until melted. Stir in half of the shredded cheese, then the reserved pasta cooking water.
Add the pasta to the sauce and toss. Pile into a casserole and top with the tomatoes and remaining shredded cheese. Bake until browned on top, 7 to 8 minutes.
In a large bowl, toss the arugula and basil with the lemon juice and a drizzle of EVOO. Serve on top of the pasta.