Boil water in a pot, add spinach, blanch briefly, then rinse under cold water. Drain and cut into 2-3 cm pieces.

In a bowl, combine spinach, tuna, and a pinch of salt and pepper.

In another bowl, beat eggs, then add milk, salt, and pepper. Mix well and add the spinach-tuna mixture.

Heat a frying pan over medium heat with salad oil. Add butter and let it melt halfway, then pour in the egg mixture. Stir gently with chopsticks until eggs are semi-cooked.