Three green bean recipes for all bean sizes from young and tender to older and tougher.
Pre-heat the oven to 450 degrees. Wash, top and tail your beans (grandma would be proud, but if you skip the tailing part, we won't tell). Dry the beans and mound them in the center of a cookie sheet large enough to later hold the beans in a single layer.
Add about a tablespoon of good olive oil and sprinkle with kosher salt and freshly ground black pepper. Move the beans around the cookie sheet with your hands like a Las Vegas dealer mixing the cards on a casino table. When all of the beans are evenly coated with the oil, arrange them in a not-too-crowded single layer on the cookie sheet.
Put the pan in the very hot oven for about 5 minutes. Check on the beans and move them around the cookie sheet with tongs, flipping some of them over to cook the other side. Keep checking on the beans every few minutes (but don't move them around too much more) until they are done to your taste; I like my beans to be limp with lots of dark roasted spots. (If you want to get fancy, you can toss the cooked beans with a little soy sauce or some finely minced garlic (or both), but I like mine just plain.)
Serve immediately or at room temperature. If no one else is home, eat the beans with your fingers.