In a large skillet with a lid, heat 2 tablespoons EVOO, two turns of the pan, over medium-high heat. Add the onion and cook, stirring, for 3-4 minutes, then add in the red pepper flakes and wilt in the kale. Season with salt, pepper and nutmeg. Pour in 1 cup chicken stock, then cover and simmer for 10-12 minutes. Uncover the pan and stir in the radishes; dress with half of the lemon juice.
While the kale is cooking, in another large skillet, heat the remaining 1 tablespoon EVOO, one turn of the pan, over medium-high heat. Season the salmon with the Old Bay. Cook the salmon fillets for 2-3 minutes on each side for pink centers, or 2 minutes longer on each side for opaque fish. Douse the salmon with the remaining lemon juice.
In a medium size saucepan with a lid, combine the remaining 1 1/4 cups chicken stock, butter and 1/2 teaspoon salt; cover and bring to a boil. Once boiling, stir in the couscous and dill. Remove from the heat, cover and let stand for 5 minutes. Fluff with a fork.
Serve the salmon fillets on a bed of spicy kale with the couscous alongside. Garnish the dill couscous with the chopped cucumber.