These Crispy Tomato Fritters Taste Like Summer on a Greek Island

Name: These Crispy Tomato Fritters Taste Like Summer on a Greek Island
Ingredients: 12 ounces tomatoes (340 g; about 3 medium tomatoes), divided; 1/2 medium yellow onion (4 ounces; 113 g), diced; 4 ounces (112 g) sheep's milk feta cheese (see notes); 1 ounce (28 g) fresh flat leaf parsley leaves and tender stems, roughly chopped (about 1/2 cup); 1/2 ounce (15 g) fresh dill fronds, roughly chopped (about 1/2 cup); 1 teaspoon dried thyme; 1 teaspoon dried oregano or marjoram; 1 large egg; 1 teaspoon Diamond Crystal kosher salt; for table salt, use half as much by volume; 1/2 teaspoon freshly ground black pepper; 3/4 cup all-purpose flour (3.3 ounces; 93 g); 4 cups (960 ml) neutral oil for frying, such as safflower, sunflower, or avocado oil (see notes); Plain whole-milk strained (Greek-style) yogurt for serving, optional