Combine hoisin sauce, honey, soy sauce, rice wine, sesame oil, five-spice powder, garlic, ginger, ketchup, brown sugar, and food colouring in a bowl to make the char siu marinade.

Place pork strips in a large dish, coat thoroughly with half the marinade, reserving the rest for glazing. Cover and refrigerate for at least 4 hours or overnight.

Remove pork from refrigerator 30 minutes before cooking to bring to room temperature.

Set up your grill for indirect smoking by lighting burners on one side only, maintaining temperature at 120-135°C. Add soaked wood chips to a smoker box or foil pouch over the heat source.

Place marinated pork on the cool side of the grill, close the lid, and smoke for 1.5 hours, maintaining consistent temperature.

Increase grill temperature to 180°C and begin basting pork with reserved marinade every 10 minutes for 30-40 minutes.

Continue cooking until internal temperature reaches 75°C when measured with a meat thermometer in the thickest part of the pork.

Move pork briefly over direct high heat for 1-2 minutes per side to achieve characteristic charred edges, basting continuously.

Rest the pork for 10 minutes, then slice against the grain into 1cm thick pieces.

Arrange on a serving platter, drizzle with any remaining glaze, and garnish with spring onions and sesame seeds.