Combine pork belly strips, water, dark soy sauce, honey, garlic and ginger in a casserole pot over low heat; bring to a gentle simmer, about 10 minutes. Cover and transfer to the oven.
Bake in the preheated oven, stirring occasionally, until pork belly is soft and tender, about 2 hours. Sprinkle spring onions and cashew nuts on top. Cover and let stand until spring onions soften, about 5 minutes.
Bring water, rice and salt to the boil in a large saucepan. Reduce heat to medium-low, cover and simmer until rice is tender, 20 to 25 minutes. Drain and rinse with tap water.
Heat olive oil in a wok over medium-high heat until smoking. Cook and stir rice until coated with oil and heated through, 1 to 2 minutes. Stir in peas, egg and 1 tablespoon soy sauce; cook until egg is set and peas are heated through, about 3 minutes.