In a large skillet, heat 2 tablespoons oil over medium high heat and cook onion for 4 minutes; add kale, crushed red pepper flakes, season with salt and pepper, and a few pinches of freshly grated nutmeg.
Add chicken stock, cover, reduce heat, and simmer 10 minutes.
Uncover and stir in radish and half the lemon juice.
Meanwhile, in another skillet, heat remaining tablespoon of oil over medium high heat.
Season salmon with Old Bay Seasoning and cook in second skillet, turning once, until cooked through, about 5 minutes; sprinkle with half the lemon juice.
In a medium saucepan, combine 1 1/4 cup chicken stock, butter, 1/2 teaspoon salt, cover and bring to a boil.
Stir in couscous and dill, remove from heat, cover and let stand 5 minutes; fluff with fork.
Serve salmon on top of kale with couscous on the side; top salmon with cucumber.