Bring a large pot of water to the boil over high heat. Add soy spaghetti and boil for approximately 2-3 minutes. Strain and immediately run under cold water until cold. Set aside to drain.
Heat a wok over high heat. Add duck breasts skin side down. Fry until the skin is very crispy, not crispy enough and it will be rubbery and tough to eat. Turn and quickly sear on the other side. Reserve duck fat in the pan.
Remove to a tray lined with baking paper and finish in the oven at 200°C for 5 minutes. Remove and set aside when finished.
Heat duck fat in wok over high heat. Add in eschalots, garlic, leek and fresh chilli and toss through.
Add in cabbage and pak choy, stir fry until vegetables have only just started to get glossy. Slice your duck thinly and add to the wok.
Add your soy spaghetti, tamari, sriracha, stevia, fish sauce, tomato paste, salt and pepper. Toss through until well combined and hot.
Serve topped with optional fried onion.