Saute or grill the asparagus until slightly tender. Let cool. Wrap each stalk with a slice of fontina and the prosciutto. Serve with an Aioli dipping sauce.
Place the egg yolk, lemon juice, garlic, and salt into a food processor. Process until well blended. With the machine running, pour in the olive oil in a steady stream and process until the mixture thickens. Scrape into a bowl and squeeze a few more drops of lemon juice over the top, stir and set aside.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.