Heat 2 tablespoons olive oil in a large Dutch oven or heavy-bottomed pot over medium heat. Add onions and season with salt and pepper. Cook, stirring occasionally, until the onions have become translucent and have totally softened, 5 to 8 minutes. Add the anchovies, if using, and cook for a couple of minutes.
Add lamb and season with salt and pepper. Add the fresh tomato. Break up the meat with a wooden spoon and stir. Cook for about 8 minutes and then add the crush tomatoesUsing a wooden spoon or a spatula, stir lamb until the fat starts to soften and the meat begins to break down. Continue to cook, stirring rather frequently until the lamb begins to brown and sizzle in its own fat, 5 to 8 minutes.
Add crushed tomatoes, stirring to scrape up any bits on the bottom of the pot. Fill the tomato can 3/4 with water. Give the can a swirl to gather up any leftover tomato sauce and add that to the sauce. Check the sauce and see if it needs more salt and pepper. Let the sauce simmer for about 1 1/2-2 hours. Add more water (1/4 cup at a time)if it seems to be getting too thick.
Cook pasta according to their direction. When pasta is cooked, drain well and immediately add some sauce to the pasta. Give it a nice stir to combine it all together. Add a little bit of olive oil on top and stir it up. Add some more black pepper (if you like)and grate on some Parmegiano Reggiano (or peccorino).