In a medium bowl, stir together the flour and salt. Make a well in the middle and crack in the eggs. Stir up the eggs with a fork, and start incorporating the flour until it’s all mixed in, and you have a soft, sticky dough. Knead for a few minutes incorporating more flour on the counter if it’s too sticky to handle, until it’s fairly soft. Wrap in plastic and let rest at room temp or refrigerate for at least half an hour.
When you’re ready to make the lasagna, heat a generous drizzle of oil in a medium saucepan and add the garlic; cook for a minute, until it starts to sizzle and turn pale golden. Add the tomatoes, squeezing them with your hands into the pot to break them up, and add their juices too, and a big pinch of salt. Simmer for about 20 minutes, until it reduces. (I find when I use some crushed or pureed tomatoes, it doesn’t take as long.) Stir in the crème fraîche or sour cream.
As it simmers, preheat the oven to 400?F. Divide the pasta dough into 6 pieces and roll each into a rounded square or rectangle about the thickness of a playing card. To assemble the lasagna, ladle some sauce into a 9x13-inch pan and spread it over the bottom. Make a layer of two pasta sheets, however they fit (to make a single layer), and top with another ladle or two of sauce, and scatter with torn basil, mozzarella and Parmesan. Repeat with more pasta, sauce, basil, cheeses, and top with another layer of pasta, sauce and cheese.
Bake for about 40 minutes, until bubbly and golden. Let stand for at least 10 minutes before serving. Serves 8ish.