Preheat the oven to 355°F (180°C) and line a baking tray with parchment paper.

Place the duck breasts skin side down onto a large, non-stick pan on a medium heat. There is no need to add oil. Leave for 15 minutes and allow the duck to render out all of its fat slowly. After 15 minutes, increase the heat to high and cook the skins for 1 minute until golden and crispy. Turn the breasts over and sear the undersides for a minute. Transfer the duck breasts skin side up onto the baking sheet. Season with salt and pepper and bake in the oven for 6-7 minutes.

Meanwhile, return the same pan used to high heat. It will still contain plenty of duck fat. Place the pak choi wedges in the pan and cook over high heat until slightly charred on all sides. I let the delicate leafy ends come up the sides of the pan to prevent them from burning.

By this time, the duck will have finished its time in the oven. Remove from the tray and place the breasts onto a cutting board to rest while you finish the pak choi. Wipe the baking tray clean, if needed, and place the pak choy on it, cut sides up. Bake in the oven for 6-7 minutes to allow them to cook more tender.

Slice the rested duck and serve with the pak choi alongside. Drizzle (or use a pastry brush to brush) a tablespoon of sesame oil over each serving. Scatter equal amounts of sesame seeds, sliced chili, and chopped cilantro over each serving. Give each person a lime wedge to squeeze over for some freshness and acidity.