Soak the liver in milk for about 30 minutes. This helps to reduce the gamey taste of the liver and it doesn’t taste strong.
Meanwhile, bring a pot of water to a boil. Place the eggs in a steamer and steam over boiling water for 15 minutes. Then submerge the steamed eggs in cold water until cooled. Then peel the eggs, cut in half and separate the egg yolks.
In a medium skillet, melt the butter over medium high heat and add minced garlic. Cook until fragrant. Drain the liver and add it into the skillet. Season with thyme, salt and pepper. Cook the liver on both sides until browned, about 2 minutes on each side. Add sherry wine and cook until the most of the liquid is evaporated and liver is fully cooked. Then place the cooked liver, chopped scallions and lemon juice in a food processor and pulse until smooth. The chicken liver pate is ready.
In a medium bowl, combined the chicken liver pate, egg yolks and mayo. Mix well. Transfer into a piping bag with star tip and pipe the filling into the egg whites. Garnish with thinly sliced scallions, if desired. Serve immediately.