How to Make It
In a small skillet, toast the peppercorns and coriander seeds over moderately high heat until fragrant, 30 seconds. Transfer to a spice grinder and let cool completely. Grind the peppercorns and coriander to a powder.
In a large bowl, combine 1/4 cup of the olive oil with the ground spices, basil, vinegar, shallot, ginger and sugar. Add the tomatoes and toss to coat with the dressing. Season the tomatoes with salt.
Light a grill or heat a grill pan. In a shallow baking dish, combine the remaining 2 tablespoons of olive oil with the rosemary. Season the bass with salt and pepper and coat the fillets with the rosemary oil. Grill the bass over moderately high heat, skin side down, until nicely charred and crisp on the bottom, 3 minutes. Turn the bass and cook until just opaque in the center, 3 minutes longer.
Using a slotted spoon, transfer the tomatoes to plates. Set the bass fillets on the tomato salad. Spoon the tomato dressing over and around the fish and serve.