Lay 2 slices prosciutto on each of 4 dinner plates. In a large bowl, whisk together 3 tbsp. oil, the vinegar, honey, and salt. Add greens and blueberries and toss gently to coat. Arrange a quarter of salad mixture on each serving of prosciutto.
Heat remaining 1 tbsp. oil in a small nonstick frying pan over medium heat. Put cheese in pan, leaving 1 in. between portions. Cook until warm and starting to brown on the bottom, about 4 minutes. Use a wide spatula to transfer cheese to the top of each salad.
Note: Nutritional analysis is per serving.