1. Saute aromatics: 

Heat vegetable oil in a large skillet over medium-high heat. 

Add minced garlic and chopped shallot to the skillet and cook until fragrant, about 1-2 minutes. 

2. Cook lamb: 

Add ground American Lamb to the skillet, breaking it apart with a spoon, and cook until browned and cooked through, about 5-7 minutes*. 

3. Combine sauce ingredients: 

In a small bowl, whisk together fish sauce, lime juice, brown sugar, and chili paste until the sugar is dissolved. 

Pour the fish sauce mixture over the cooked lamb in the skillet and stir to combine. 

Cook for another 2 to 3 minutes, allowing the flavors to meld together. 

4. Final steps : 

Remove the skillet from heat and stir in sliced green onions, chopped cilantro, and chopped mint. Season with salt and pepper to taste. 

5. Serving: 

To serve, spoon the lamb larb mixture into butter lettuce leaves, creating lettuce cups. Serve the Lamb Larb with the lettuce leaves, fresh herbs, lime and chopped peanuts.