In a small skillet over low heat, melt the butter. Add the green onions and garlic. Cook for 2 minutes.
In a medium bowl, place the flaked fish, mashed yuca, cooked onions and garlic, bread crumbs, cilantro,mustard, cumin, red pepper flakes, salt and pepper and mix well.
In a separated bowl, whisk together the cream and eggs until well blended. Add to the fish mixture and mix well.