Bring a large pot of water to a boil, salt it, add the pasta and cook until al dente. Drain, reserving about 3/4 cup of the pasta cooking water. While the pasta is working, in a large skillet, heat the EVOO, 3 turns of the pan, over medium heat. Add the pancetta, season with 1 tsp. black pepper and cook until lightly browned. Stir in the scallion whites, chile pepper (if using) and garlic. Zest the lemon over the pan, stir in the thyme and cook for 3 minutes. Add the wine and cook until reduced by half, 1 to 2 minutes. Turn the heat to low.
In a medium bowl, beat the reserved pasta cooking water with the egg yolks to temper them. Add the juice of the lemon, the parsley and scallion greens to the skillet.
Add the pasta to the skillet, turn off the heat and pour in the tempered eggs. Sprinkle in a small handful of each of the cheeses and toss vigorously for 1 minute until the sauce coats the pasta and is thick and shiny. Serve in shallow bowls with a little extra cheese, the basil and tomato on top.