In a Dutch oven, heat olive oil over medium heat. Add onion and cook until they become translucent, about 5-8 minutes. Take the carrot slices, bay leaves, celery slices and fresh thyme and tie all together with butcher string. This is a “bouquet garni” which means ingredients that will infuse their flavor into the soup. Add the bouquet garni, minced garlic and prosciutto and cook for another 10 minutes. Stir often.
Add 1 quart of the chicken stock, and the lentils. The stock should cover the veggies and lentils. If it doesn’t, add more stock, until the veggies are covered. Season with salt and pepper and bring to a boil. After it reaches a boil, reduce heat and simmer for about 25 minutes, until the lentils are cooked.
Stir in the lettuce and give it a stir. Cook for a minute or two. If the soup is too thick, add more stock, one cup at a time, until the soup reaches the consistency you like.
Remove the bouquet garni before serving.
Ladle the soup into bowls, drizzle with a bit more olive oil, sprinkle with Asiago cheese and parsley. Serve immediately.