In a medium bowl, whisk together ½ cup of all-purpose flour, 1 tsp. of baking powder, ½ tsp. of kosher salt, and 1 tsp. of freshly ground black pepper. In another bowl, lightly beat 2 large eggs. In a third bowl, put 2 cups of panko or breadcrumbs.
In a separate bowl combine 2 Tbsp. of extra-virgin olive oil and 1 Tbsp red wine vinegar or fresh lemon juice, and 1 teaspoon of mustard. Season with salt and pepper to taste. In a large bowl, toss 10 oz. of spring greens salad and toss with the dressing.
Slice 2 fresh mozzarella cheese balls into eight pieces total, each ½" thick. Coat each slice with seasoned flour, shaking off any excess. Then, dip each slice in beaten eggs, letting the extra egg drip off.
Repeat the flour and egg coating one more time. Finally, cover each slice with panko breadcrumbs, pressing lightly to make them stick.
Shake off any excess breadcrumbs and place the coated cheese slices on a plate.
In a medium skillet over medium heat, heat the remaining 4 Tbsp. of olive oil and pan fry the mozzarella slices in two batches, flipping them once, until they are golden brown on both sides, about 5–7 minutes per batch.
Drain them on paper towels, and keep them warm in the oven, until ready to serve.