Pat the fish fillets dry with a paper towel and season both sides with salt and black pepper. Set them aside.

In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté for 3 to 4 minutes, stirring occasionally, until the onion is softened.

Stir in the minced garlic, grated ginger, and red curry paste, cooking for an additional minute until fragrant.

Pour in the coconut milk and your choice of chicken or vegetable broth. Stir to combine and bring the mixture to a gentle simmer.

Add the seasoned fish fillets to the simmering liquid. Cover partially and cook for 8 to 10 minutes, or until the fish is opaque and flakes easily with a fork.

Stir in the fish sauce and lime juice. Adjust the seasoning with salt, pepper, or lime juice to taste.

Ladle the soup into individual bowls. Garnish with chopped cilantro and serve with lime wedges on the side.