Heat olive oil in an oven-safe skillet over medium-high heat. Sear the sea bass for 2-3 minutes per side.
Transfer the skillet to the preheated oven and bake for 10-12 minutes, or until the fish is cooked through.
While the fish is baking, prepare the avocado salsa by combining diced avocado, red onion, tomato, lime juice, and cilantro in a bowl. Season with salt and pepper to taste.
Serve the baked sea bass topped with avocado salsa.
Notes
Serve immediately for the best flavor. Garnish with extra cilantro if desired.