Preheat the oven to 400F. Wrap the beets in aluminum foil (individually) and bake for 40 minutes or until you can easily insert the tip of a knife all the way through. Let them cool in the foil for a few minutes. Then peel and set aside.
Place the lentils in a pot and cover them with cold water (3 inches over the top of the lentils). Cover the pot and heat over medium high heat. Bring the water to a boil and reduce heat to medium low and simmer for 15 to 20 minutes until lentils are tender but not mushy. Drain them and rinse in cold water.
In a medium bowl, whisk together the finely diced apple, shallot, mustard, maple syrup, apple cider vinegar, olive oil, salt and pepper.
Arrange the bitter greens, topped with sliced beets, lentils, prosciutto, cheese and drizzle with enough vinaigrette to coat all the ingredients. You might not need all of it. Personally, I prefer less vinaigrette.