People tend to have strong preferences about congee. My grandmother made it thick and hearty, but I now prefer the thinner, lighter versions you get in Hong Kong. It's easy to adjust the consistency: if it's too thick, stir in more water; too thin, cook it longer.
I like to mix long grain and short grain rices (not glutinous rice, but the type used for Japanese and Korean cuisines), which makes the congee smoother. Yau ja gwai, often called Chinese doughnuts or crullers, come in pairs.
Dried scallops (conpoy) are expensive, but a little goes a long way. Buy the largest ones you're willing to pay for - the small ones are much tougher.
Fish paste is sold by Chinese fresh seafood vendors, who make it from carp and whatever types of fish were left over from the day before.
Put the short grain and long grain rice in a medium-sized pan and rinse with several changes of water. Drain off most of the water, then add 1.5 litres of fresh water. Briefly rinse the dried scallops then add them to the pan. Cut the ginger into two pieces. Put the ginger and the spring onions into the pan. Bring the water to the boil then lower the heat, cover partially with the lid and simmer for about 90 minutes, stirring frequently.
While the congee is cooking, season the fish paste. Finely mince the spring onions, and roughly chop the fresh coriander, then mix them into the fish paste.
When the congee has cooked for 90 minutes, test the consistency, and adjust it by adding more water, or by letting it simmer longer with the lid off the pot, stirring often. When it’s the correct consistency, season to taste with salt. Remove the ginger and spring onions from the congee, but leave in the dried scallops (which should be in fine shreds at this point).
Scoop heaped teaspoonfuls of the fish paste mixture into the congee and let them poach over a low flame for about 15 minutes, or until cooked through. Slice the lettuce leaves into 1cm-wide strips, add them to the congee then stir until they’re wilted.
Preheat the oven to 180°C (350°F). Heat the yau ja gwai for about five minutes, then slice them about 5mm (¼in) thick. Ladle the congee into bowls then let each diner top their portion with chopped spring onion, coriander leaves, julienned ginger, white pepper and the yau ja gwai.