Heat a large pan over medium heat.
Add the green curry paste and sauté for 1-2 minutes until fragrant.
Pour in the coconut milk and stir well.
Bring the mixture to a simmer.
Add the chicken or tofu and cook for 5-7 minutes until cooked through.
Stir in the eggplant and bell peppers, cooking for another 5 minutes.
Add the spinach and cook until wilted.
Stir in the fish sauce and brown sugar, adjusting to taste.
Remove from heat and garnish with fresh basil leaves.
Serve hot with lime wedges on the side.