Step 1 Preheat oven to 200°C. Line a large baking tray with baking paper. Place sweet potato halves on prepared tray and roast for 1 hour, or until very tender. Cut each piece of cooked potato in half, scoop flesh into a medium bowl and mash until smooth.
Step 2 Set a wok (or large non-stick frying pan) over high heat and heat rice bran oil. Add chopped garlic to wok with sliced shallots (white part only) and coriander stems; stir for a few seconds, or until garlic is translucent.
Step 3 Add chicken mince to wok (or pan), breaking it up with a wooden spoon, and cook for 1 more minute, or until mince browns; season with pepper.
Step 4 Add capsicum to wok (or pan), then stir in soy sauce and oyster sauce; cook for 2 more minutes, or until almost all the liquid has evaporated. Remove wok from heat. Stir carrot and sprouts into san choy bao mixture.
Step 5 Divide mashed sweet potato and san choy bao mixture among 4 serving bowls. Garnish salad with sliced green shallots and coriander leaves, and serve.