Combine chicken, lemongrass, ginger, fish sauce, garlic and 2 tablespoons of curry paste in a large bowl. Mix well and marinade for 60 minutes.
Heat olive oil in a large fry pan or crockpot.
Add chicken and remaining curry paste and fry off until chicken is lightly browned - about 5 minutes
Add stock and coconut milk and stir until combined. Then add carrot and sweet potato.
Bring to the boil, the simmer partially covered for 45-60 minutes or until carrot and sweet potato are cooked. I tend to simmer covered for half the cooking time, then uncovered for the other half. If it's getting too thick, place the lid back on for remaining cooking time.
Serve with jasmine rice, naan and a garnish or cilantro