This dish will be very warm, not hot. The success of this recipe depends on high-quality ingredients, including ripe, in-season tomatoes and a fruity olive oil (the test kitchen prefers Columela Extra-Virgin). Don’t skip the step of freezing the mozzarella, as freezing prevents it from turning chewy when it comes in contact with the hot pasta. If handmade buffalo- or cow’s-milk mozzarella is available (it’s commonly found in gourmet and cheese shops packed in water), we highly recommend using it, but skip the step of freezing and add it to the tomatoes while marinating. Additional lemon juice or up to 1 teaspoon sugar can be added at the end to taste, depending on the ripeness of the tomatoes.
1. Whisk oil, 2 teaspoons lemon juice, garlic, shallot, 1/2 teaspoon salt, and 1/4 teaspoon pepper together in large bowl. Add tomatoes and gently toss to combine; set aside. Do not marinate tomatoes for longer than 45 minutes.
2. While tomatoes are marinating, place mozzarella on plate and freeze until slightly firm, about 10 minutes. Bring 4 quarts water to rolling boil in stockpot. Add 1 tablespoon salt and pasta, stir to separate, and cook until al dente. Drain well.
3. Add pasta and mozzarella to tomato mixture and gently toss to combine. Let stand 5 minutes. Stir in basil; adjust seasonings with salt, pepper, and additional lemon juice or sugar, if desired, and serve immediately.