Prep ingredients: Peel shallot, then finely chop 2 tablespoons (save remaining for own use). Trim ends from green beans. Thinly slice chives. Scrub potatoes, then cut into ½-inch pieces.

Cook & season potatoes: In a small saucepan, cover potatoes with 1 inch of water and season with 2 teaspoons salt. Cover and bring to a boil, then uncover and cook until easily pierced with a fork, about 5 minutes. Drain potatoes and return to saucepan. Gently stir in sour cream, chives, and 1 tablespoon butter. Season to taste with salt and pepper. Cover to keep warm.

Make vinaigrette: In a medium bowl, combine chopped shallots and 1½ teaspoons vinegar. Whisk in 2 tablespoons oil, then season to taste with salt and pepper.

Cook & dress green beans: Heat 1 tablespoon oil in a medium nonstick skillet over medium-high. Add green beans to skillet, then season with salt and pepper. Cook until tender and browned in spots, 4–5 minutes. Transfer to bowl with vinaigrette and stir to coat. Wipe out skillet and return to stovetop.

Season salmon: Pat salmon very dry, then season both sides with salt and pepper. Sprinkle 2 teaspoons of the everything bagel seasoning over top, pressing gently to help seasoning adhere. Heat 1 tablespoon oil in same skillet over medium-high until shimmering.

Cook salmon & serve: Reduce heat to medium. Add salmon, skin side down (salmon should sizzle). Press each fillet firmly with a spatula for 10 seconds. Cook, occasionally pressing gently on fillets, until skin is well browned and crisp, and salmon is almost cooked through, 5–7 minutes. Flip salmon and cook until just medium, 1–2 minutes more. Serve with potatoes and green beans alongside.