In a large pot, heat 2 tablespoons of vegetable oil over medium-high heat. Once hot, add the boneless lamb and sear for 5–7 minutes until browned.

Reduce heat to medium and add one chopped onion and minced garlic. Sauté for 5 minutes until the onion is translucent and golden.

Stir in garam masala, yellow curry powder, cumin seeds, and salt. Cook for 1 minute until the spices release their aromas.

Pour in coconut milk and tomato paste, then add potatoes and carrots. Stir everything together well.

Increase heat slightly until the mixture simmers. Cover and reduce heat to low. Cook for about 1 hour and 55 minutes, stirring occasionally.

For slow cooker method, transfer mixture to a slow cooker after Step 2. Cook on high for 4-6 hours or low for 8-10 hours.

Ladle the curry into bowls and garnish with cilantro. Serve hot with rice or naan.