1. Prepare the marinade: 

In a small bowl, mix together garam masala, olive oil, minced garlic, salt, and pepper to create a marinade. 

2. Marinate loin chops: 

Rub the marinade all over the American Lamb loin chops ensuring they are evenly coated. Let them marinate for at least 30 minutes at room temperature, or cover and refrigerate for up to 4 hours for maximum flavor. 

3. Grill: 

Preheat your grill to medium-high heat. 

Once the grill is hot, place the loin chops on the grill and cook for about 4-5 minutes per side, or until they reach your desired level of doneness. Use a meat thermometer to ensure they reach an internal temperature of 145°F (63°C) for medium-rare or 160°F (71°C) for medium*. 

Once cooked, remove the loin chops from the grill and let them rest for a few minutes before serving. 

4. Prepare the mint raita: 

In a bowl, combine plain yogurt, grated cucumber, chopped mint leaves, chopped cilantro leaves, ground cumin, lemon zest and juice, sugar, and salt. Mix well until everything is evenly incorporated. 

Taste the raita and adjust the seasoning with more salt if needed. 

Cover the bowl and refrigerate the mint raita for at least 30 minutes to allow the flavors to meld together. 

Serve the chilled mint raita alongside the grilled garam masala loin chops as a refreshing and cooling accompaniment. 

5. Serving: 

Arrange the grilled garam masala loin chops on a platter and serve with a bowl of mint raita on the side.