In a shallow pan, combine chopped potatoes and salt. Roast for 20 minutes.
Push the potatoes to the edges of the pan. Add the salmon in the center. Rub with olive oil and salt. Put back in the oven.
While the salmon cooks, melt the butter in sauce pan over medium heat. When it's toasty and turning golden, add the lemon zest and juice.
When salmon is cooked, pour the burnt butter over the top and serve immediately with dressed greens.