Peel the cucumber and halve it lengthwise. Scoop out the mature center seeds with a spoon — they turn hard and woody when cooked. Cut the cucumber into thick, long strips. Slice the vegetarian fish thinly and the shiitake into strips.

Heat the oil in a wok over medium-high heat until shimmering. Add the shiitake and vegetarian fish and fry for about 1 minute, then stir and continue until both turn golden and deeply fragrant, about 2 minutes total.

Toss in the cucumber strips and stir-fry briefly. Drop the heat to medium-low and add the toon paste, soy sauce, white pepper and salt. Turn the heat back up to high and stir-fry quickly until the seasonings smell toasted and aromatic.

Pour in 60 ml of water, cover, and simmer on medium-low for about 3 minutes. Flip the cucumber pieces so they cook evenly, then add the remaining 60 ml of water. Cover again and simmer on medium-high for about 5 minutes, until the cucumber is soft, glossy and seasoned and the liquid has nearly cooked away.

Turn off the heat and transfer everything to a serving plate. Scatter a pinch of goji berries on top for color, and serve hot with steamed rice.