How to Make It
Arrange prosciutto in a skillet; place pan over medium-high heat. Cook 4 minutes or until crisp.
Heat olive oil in a large stockpot over medium heat. Add leek and garlic; cook 30 seconds, stirring frequently. Add potato; cook 4 minutes, stirring frequently. Add artichokes and stock; bring to a simmer. Cover and simmer 25 minutes or until vegetables are tender, stirring occasionally.
Reduce heat to medium-low. Stir in half-and-half, salt, and 1/4 teaspoon pepper. Remove from heat; let stand 5 minutes. Transfer soup to a blender. Remove center piece from blender lid (to allow steam to escape); secure lid on blender. Place a clean towel over opening in lid. Blend until smooth.
Return soup to pan over medium-low heat. Stir in butter and vinegar. Cook until warm, stirring frequently. Ladle soup into 12 serving bowls. Sprinkle evenly with remaining 1/4 teaspoon black pepper and thyme. Garnish with crisped prosciutto.