Sprinkle the grouper steaks on both sides with 1/8 teaspoon of the pepper. In a large, nonstick frying pan, heat 1 1/2 teaspoons of the olive oil over medium-high heat. Add the fish to the pan and sear on both sides until lightly browned, about 2 minutes a side. Transfer to a plate and keep warm.
Reduce the heat to medium and add the remaining 1 tablespoon olive oil to the pan. Add the onion and saute until soft and lightly golden, about 6 minutes. Add the garlic and saute until softened, about 1 minute. Add the tomatoes, olives, capers and jalapeno and simmer for 10 minutes to allow the flavors to blend. Stir in the remaining 1/8 teaspoon pepper. Return the fish to the pan. Cover and simmer until the fish is opaque throughout when tested with the tip of a knife, 6 to 8 minutes.
Transfer the grouper steaks to warmed individual plates. Stir the lime juice into the vegetables and pan juices. Spoon some sauce over each steak. Serve immediately.