Rinse the tilapia under cold water and pat dry with paper towels. If using whole fish, make 2–3 diagonal slashes on each side to allow marinade penetration. Place fish in a dish large enough to hold it flat. In a small bowl, combine 3 tbs vegetable oil, 2 tbs lime/lemon juice, 2 tsp salt, 1 tsp black pepper, 1 tsp paprika, 2 minced garlic cloves, and 2 tbs chopped thyme or parsley. Rub the marinade all over the fish and into the slashes and cavity (for whole fish). Cover and refrigerate for 20–30 minutes (up to 1 hour).

Grill or pan-fry the fish

For grilling: preheat grill to medium-high (about 200–230°C / 400–450°F). Oil the grill grates to prevent sticking. Place the fish directly on the grill (use a fish basket or foil if using fillets). Grill whole fish 6–8 minutes per side depending on thickness, until flesh flakes and internal temperature reaches 63°C (145°F). For fillets, grill 3–5 minutes per side. For pan-frying: heat a large skillet over medium-high heat and add 1–2 tbs vegetable oil. When shimmering, add fish. Cook whole fish or fillets 4–6 minutes per side (thicker pieces longer) until golden and cooked through. Transfer cooked fish to a plate and tent with foil while you finish other components.

Tomato sauce (optional)

Make the tomato sauce

Heat 2 tbs vegetable oil in a saucepan over medium heat. Add 1 finely chopped yellow onion and sauté 4–5 minutes until translucent. Add 2 minced garlic cloves and cook 30 seconds until fragrant. Stir in 3 cups chopped tomatoes and 1 tbs tomato paste. Season with 1 tsp salt, 1 tsp black pepper, 1 tsp dried oregano and 1 tsp sugar. Add 120 ml water or stock to loosen. Bring to a gentle simmer and cook 10–12 minutes, stirring occasionally, until sauce reduces and thickens slightly. Taste and adjust seasoning. Optionally blend briefly for a smoother sauce or leave chunky.

Finish and keep warm

If you want a brighter flavor, stir in 1 tsp fresh lime juice and 1 tbs chopped fresh herbs at the end. Keep the sauce warm on very low heat until ready to serve. Spoon over fish or serve on the side.

Seasoned onions & fresh tomato (side)

While the fish marinates or cooks, prepare the onion-tomato salad. Thinly slice 1 onion and place it in a bowl of cold water for 5 minutes to soften the bite, then drain and pat dry. Add 1 diced ripe tomato, 1 tbs chopped cilantro/parsley, 1 tbs olive oil, 1 tbs lime/lemon juice, 1/2 tsp salt and 1/2 tsp black pepper. Toss to combine and let sit for at least 5 minutes to marry flavors. Taste and adjust seasoning. Serve chilled or at room temperature alongside the fish.

Optional side - fried plantains or rice

Fried plantains

If frying plantains, heat approx. 500 ml vegetable oil in a heavy skillet to medium-high (about 170–180°C / 340–350°F). Slice ripe plantains diagonally into 1/2-inch slices. Fry in batches without crowding until golden brown, about 2–3 minutes per side. Remove to paper towels and sprinkle with a pinch of salt. Serve hot.

Rice

If serving rice, prepare 4 cups steamed white rice according to package instructions (typically 2 cups rice + 4 cups water yields about 4 cups cooked). Keep warm until serving.

To serve

Place a portion of rice or fried plantains on each plate (if using). Lay the grilled or fried tilapia on top or alongside. Spoon warm tomato sauce over the fish or serve it on the side. Add a generous spoonful of the seasoned onions and fresh tomato alongside for brightness. Garnish with extra chopped herbs and lime wedges. Serve immediately.