Place frozen or fresh yuca in a medium pot and cover with water. Bring to a boil over medium high heat, reduce heat slightly and boil for 45 minutes to 1 hour or until very tender.
Remove from heat. Add 1 teaspoon of salt and allow to sit in salted water until slightly cooled.
Remove woody stems (they should separate relatively easily) from the yuca and discard. Place yuca in serving dish.
In a small skillet , heat 2 tablespoons of olive oil over medium heat. Add sliced onion. Sauté until softened, but not caramelized, about 4-6 minutes. Remove from heat.
Heat ¼ cup olive oil in a small saucepan until warmed. Add garlic and ½ teaspoon sea salt, whisk together. Set aside.
Pour olive oil and garlic mixture over yuca. Top with softened onion slices. Squeeze fresh lime juice over yuca. Serve hot.