Pulled Lamb Sandwich With Caramelized Onions And Chipotle Garlic Aioli

Name: Pulled Lamb Sandwich With Caramelized Onions And Chipotle Garlic Aioli
Ingredients: 1 1/2 - 2 lbs boneless leg of lamb; 3/4 chicken stock; 1 1/2 teaspoon rosemary; 1 tablespoon olive oil; 2 cloves of garlic (smashed); 1 1/2 tablespoon balsamic vinegar; 1 teaspoon cracked black pepper; 1/2 teaspoon red pepper flakes; 4 cups thinly sliced; 1 1/2 tablespoons olive oil (or butter); 1 1/2 teaspoon salt; 1 1/2 teaspoons sugar; 2 tablespoons Chipotle and Roasted Garlic Paste; 1/2 tsp salt; 1 large egg yolk, at room temperature; 1/2 cup (250ml) extra-virgin olive oil; 1/2 cup pure olive oil