Combine curry powder, cumin, garlic, ½ teaspoon salt and pepper. Rub salmon filets with the spice mixture and set aside.
Drizzle sunflower oil into an ovenproof skillet and heat over high heat. Add the salmon filets skin side up and sear for 2 to 3 minutes. Use a spatula to flip the filets onto the skin side. Transfer the skillet to the oven and bake for 5 to 7 minutes, until the salmon is medium-rare.
While salmon is baking, heat the coconut oil in a skillet. Add onions and sauté over medium heat for 2 to 3 minutes. Add mushrooms and ½ teaspoon salt and continue to sauté for 2 minutes. Add chard and sauté with the other ingredients until the greens begin to wilt, about 2 minutes.
To serve, divide the greens into 4 equal portions on plates. Carefully slip the salmon away from the skin and place the filets on top of the greens.