Heat a medium saucepan over moderate heat for 1 minute. Pour in the olive oil and turn the heat down to low. Add the rosemary sprig and the crumbled chile. When the rosemary begins to sizzle, add the garlic. Cook for 1 minute or so, then add the lima beans and 1/2 teaspoon of salt. Stew gently for 5 to 7 minutes, until the limas are soft, but not mushy. Drain the beans, reserving the oil. Discard the rosemary sprig and chile.