To make the curry paste, place the red onion, garlic, ginger, lemongrass and chili in a mortar and pestle and mash until it becomes a paste, stir in spices and oil. Or, add all ingredients to a small food processor, blend until it becomes a paste.

Marinate the chicken in the paste for at least 30 minutes, or overnight in fridge.

Pour the drained tomatoes and coconut milk into the slow cooker stir well to combine, next add the onions and sweet potatoes, then the chicken on top. Stir together.

Cover and cook on low for 5 hours or until internal temperature of chicken reads 165°F.

When finished cooking, add fresh lime juice and stir to combine. Garnish with cilantro, if desired.

Serve with a side of steamed green beans or broccoli and Jasmine rice to soak up all the delicious sauce.