In a large heavy skillet, heat the oil over high flame. Brown the lamb, breaking it apart with your spatula into small pieces, until the fat is rendered and the meat has begun to develop a crust, 5 minutes, stirring occasionally. Push the lamb to the sides of the pan and add half of the onion, garlic and ras el hanout to the center. Cook, eventually stirring the lamb and veggies together, until the onion is soft, another 3 minutes.
Remove from the heat and stir in the salt, harissa and lemon juice. Taste for seasoning and add more salt, acid or heat as necessary.
Make the aioli: In a small mixing bowl or food processor whisk or pulse the egg yolk, lemon juice, and garlic until smooth. Working slowly, add 1 teaspoon of the olive oil and whisk or pulse until incorporated. Repeat with 3 additional teaspoons. Once the oil is taking, slowly drizzle in the remaining olive oil. Once the mixture is thick, add the mint leaves and season with the salt.
To serve, arrange the lettuce cups on a platter and divide the lamb mixture between them. Garnish with the radishes, remaining red onion, and mint leaves, and serve alongside the lemon-mint aioli.
Recipe Notes: There are plenty of modifications for this recipe if you don’t own one of the specialty ingredients. For the harissa, substitute 1/4 teaspoon cayenne pepper, and add it to the pan with the ras el hanout. If you don’t have ras el hanout, you can create a similar spice blend by combining 1/4 teaspoon each of ground cumin, turmeric, coriander and cinnamon. You can also make the aioli with store bought mayonnaise if you don’t want to bother with the from scratch version. Simply combine 1/4 cup mayonnaise with 1 tablespoon lemon juice, 1/4 cup finely chopped fresh mint, and season to taste with salt.
