1. Heat butter in a large high-sided skillet over medium heat until melted. Add garlic, ginger, salt, coriander seeds, cumin seeds, turmeric, and cayenne. Cook, stirring constantly, until fragrant, about 30 seconds. Add white wine, and bring to a rolling simmer over medium-high; cook for 1 minute. Stir in coconut milk, and return to a simmer. Once simmering, reduce heat to medium-low.
2. Gently place salmon, skin side up, in poaching liquid in skillet. Simmer, flipping once halfway through, until just cooked, about 6 to 8 minutes depending on thickness, adjusting heat as necessary to maintain a bare simmer. Carefully transfer salmon to a plate, and tent with foil to keep warm.
3. Remove and discard ginger and garlic from skillet using a slotted spoon. Increase heat to medium-high, and cook until coconut poaching liquid is reduced by half, about 8 minutes. Stir in tomatoes, corn, and dill, and cook for 1 more minute. Serve salmon with coconut sauce and additional dill.