Trim the dark ends off the fiddleheads, some of them may not need this.
Place your fiddleheads in a colander and rinse or spray them with cold water. Then place them in a bowl of water and rub to remove all of their papery-like coverings. Drain and rinse.
Bring a large pot of salted water to a boil. Cook fiddleheads in the boiling water until barely tender, 3-5 minutes; drain and pat dry on a kitchen towel.
Heat butter or ghee and olive oil in a large skillet over medium heat.
Add the prepared fiddlehead ferns. Cook and stir until ferns are tinged lightly brown and around the edges, about 3 minutes.
Add garlic, salt and pepper. Cook stirring constantly until the garlic is fragrant and just lightly brown.
Remove from heat and sprinkle with lemon juice. Serve warm.