Scrape black clay from salted egg. Rinse thoroughly. Cook in gently simmering water for 10 minutes. Remove to cold water to cool down. Cut into two halves. Remove egg from shell with a spoon. Dice 1 cm.
1 salted egg
Peel century egg. Rinse and pat dry with paper towel. Dice 1 cm.
1 century egg
Remove roots from spinach. Wash thoroughly and drain. Cut 7-8 cm (3 inches) long. If stems are old and woody, break them by hand instead. Tear off some of the peel on the stems as you do so. This helps make the stems more tender.
350 g Chinese spinach (yin choi, 苋菜)
Gently simmer spinach in chicken stock, covered, till just soft and still quite green, 3-4 minutes. Add or reduce stock as necessary. There should be enough to cover 30-40% of the spinach.
1 cup chicken stock (unsalted)
Drizzle with light soya sauce. Stir gently to mix well. Remove spinach to a deep plate, leaving stock in the pot.
2½ tsp light soya sauce
Add diced salted and century eggs to chicken stock. Bring back to a boil. Simmer for 30 seconds, stirring gently.
Taste and adjust seasoning if necessary. Pour eggs and stock over spinach. Serve immediately.