Bring 4 quarts of water to a boil in a large pot and dissolve the coarse sea salt.
Cook the spaghetti for 2 minutes less than the package instructions so it stays very firm.⏱ 2 min
Warm the olive oil in a wide skillet over medium heat.
Add half the lemon zest and half the lemon juice to the warm oil.
Tear half of the herb leaves directly into the warm skillet.
Use tongs to transfer the undercooked pasta directly into the skillet.
Ladle 1 cup of starchy pasta water into the skillet and turn heat to high.
Stir and toss vigorously for 2 minutes until the liquid reduces into a glossy glaze.⏱ 2 min
Turn off the heat completely and remove the pan from the burner.
Add the grated Pecorino and remaining lemon juice, tossing rapidly until silky and emulsified.
Plate immediately, topping with remaining lemon zest, black pepper, and fresh herb leaves.
Preheat your oven to 350°F (175°C) and line a rimmed baking sheet.
Toss the torn bread on the baking sheet with 1 tablespoon of olive oil and a pinch of salt.
Bake the bread for 12 to 15 minutes until dried and crisp outside but slightly chewy inside.⏱ 15 min
Place the cut tomato wedges in a colander set over a large mixing bowl.
Sprinkle 1 teaspoon of kosher salt over the tomatoes and toss gently.
Let the tomatoes rest for 15 minutes to collect all their juices in the bowl below.⏱ 15 min
Whisk the vinegar, grated garlic, black pepper, and remaining olive oil directly into the drained tomato juices.
Add the sliced cucumber and thinly sliced red onion into the bowl with the vinaigrette.
Add the toasted bread and salted tomato wedges to the bowl.
Tear the fresh basil leaves into the bowl and toss thoroughly to coat the bread.
Let the salad stand at room temperature for 15 minutes before serving so the bread absorbs the dressing.⏱ 15 min