Sauteed green beans with radishes and fennel seed

1 lb. green beans, trimmed
1 tbsp. virgin olive oil
1 tbsp. unsalted butter
2 tsp. fennel seeds
4 oz. radishes, trimmed and sliced into 1/2-inch rounds (about 1 cup)
3 scallions, trimmed and thinly sliced
1/4 tsp. salt
freshly ground black pepper
1 tbsp. fresh lime or lemon juice

In a large saucepan, bring 2 quarts of water to a rapid boil. Add the beans and, after the water returns to a boil, cook them for four minutes. Remove them from the pan and refresh them under cold running water to preserve their color. Drain the beans and set aside. In a large, heavy-bottomed skillet, heat the oil and butter over medium-high heat. When the butter has melted, add the beans and the fennel seeds. Sauté for three minutes, stirring frequently. Add the radishes, scallions, salt, pepper, and lime or lemon juice. Sauté, stirring constantly, until the beans are tender but crisp – about three minutes more. Serve immediately. Serves 6