Combine the soy sauce and ginger in a shallow bowl and add the salmon; set aside to marinate while you cook the beans and spinach.
Heat 2 tablespoons of the olive oil in a saucepan or deep skillet over medium heat. Add the garlic and cook until sizzling and softened but not browned. Stir in the beans (no need to drain them if they arent swimming in liquid) and simmer for 5 minutes. Stir in the scallions and spinach and reduce the heat to low.
Heat a large nonstick skillet over medium-high heat and add the remaining 2 tablespoons of olive oil. Lift the salmon fillets out of the marinade and cook until nicely browned and a little pink in the center, about 4 minutes per side.
Serve the salmon hot with the beans and spinach.