Combine 1 teaspoon of salt, 1 teaspoon of black pepper, 2 tablespoons of garlic powder, and 1 cup of breadcrumbs in a bowl. Stir and set aside.
Pour 1 cup of flour into a shallow bowl or on a plate and set aside.
Combine 3 eggs and ½ cup of buttermilk in a bowl. Dip the tomatoes in the flour, then the egg mixture, then the breadcrumbs. Repeat until all tomatoes are coated in the breadcrumb mixture.
Heat 2 cups of vegetable oil in a large pot over medium heat. Once the oil is hot, add tomatoes in batches and cook 2 minutes per side. Repeat until all of the tomatoes are fried.