Trim and rinse fiddleheads, removing any brown ends or mushy parts. In a large pot bring 2 quarts water to a boil. Add salt and fiddleheads. Cook 1 minute. Drain and rinse with cold water. In a large frying pan, heat oil over medium-high heat. Add fiddleheads. Cook, stirring, until they start to brown, about 5 minutes. Add garlic if you like, and cook, stirring about 1 minute. Salt to taste. Serve immediately.