Return the skillet to medium heat and add ½ Tb olive oil, ½ tsp salt, and the sliced green onions. Stir and cook until onions smell fragrant and look wilted. Add chicken broth, lemon juice and capers. Simmer for 4 minutes to reduce the sauce. Whisk in butter and mustard until combined. Spoon the sauce over the salmon and serve warm.
1 ½ tsp. kosher salt, 2 Tb olive oil, 4 green onion white parts, sliced thin, ⅓ cup chicken broth and more to thin sauce as needed, 3 Tb freshly squeezed lemon juice, 1 Tb Buzz Savories Spicy Beer Mustard, 2 Tb capers, drained, 2 Tb unsalted butter