If using fresh edamame (skip this step with frozen soybeans), bring a large pot of salted water to a boil. Add edamame and boil 2 minutes. Drain and let cool.
Heat a large skillet (preferably cast iron) over high heat. Toss in edamame, half at a time, and roast, turning with tongs, until blackened in several spots, 5 to 8 minutes. Pour into a bowl, toss with salt to taste, and serve immediately. To eat, pop peas out of pods with your fingers or teeth.
Note: Nutritional analysis is per 1/2-cup serving.