Prep the tilapia: Pat fillets dry.
Brush lightly with oil, and season both sides with salt and pepper. Set aside while you preheat.
Preheat the broiler: Move an oven rack 6 inches from the heat source. Line a sheet pan with foil and lightly oil it.
Start the sauce base: In a skillet over medium heat, warm a tablespoon of oil.
Add garlic and ginger. Cook 30–60 seconds until fragrant, not browned.
Add curry paste: Stir in the Thai red curry paste and cook for 1 minute to bloom the spices.
Pour in coconut milk: Whisk until smooth. Simmer gently for 3–5 minutes to thicken slightly.
Season the sauce: Add fish sauce (or soy sauce), brown sugar, and the juice of half a lime.
Taste and adjust. You want a balanced mix of salty, sweet, tangy, and spicy.
Optional veggies: If using bell pepper or snap peas, add to the sauce and simmer 2–3 minutes until crisp-tender. For spinach, stir it in at the end just to wilt.
Broil the tilapia: Place seasoned fillets on the prepared pan.
Broil 5–7 minutes, depending on thickness, until the fish flakes easily and the edges have a light golden color.
Finish with lime: Squeeze a little lime over the cooked fish for brightness.
Serve: Spoon warm curry sauce over tilapia. Garnish with cilantro or basil. Add rice and lime wedges on the side.