In a large skillet or sauté pan, melt the butter over medium-high heat. Add the green beans, spreading them as evenly as possible in the pan, and sprinkle with apinch of salt. Cook for 2 minutes without disturbing them, then toss, sprinkle with salt, and cook for 2 minutes longer.
Pour in ¼cup (60ml) water, cover, and cook for 4 minutes, then uncover and cook, tossing occasionally, until the beans are tender and blackened in spots, about 3 minutes longer. Serve.