For the Quick Pickled Onions:
2 In a mason jar, combine the onions, vinegar, salt, peppercorns and boiling water. Stir to incorporate, cover loosely and let sit at room temperature for at least 30 minutes. Once cooled, they can be refrigerated up to 5 days.
For the Orange Gochujang Duck Breast:
5 Using a sharp knife, lightly score the fat of each duck breast in a crosshatch pattern making sure not to penetrate the flesh. Evenly season the fat side with salt then flip and season the meat side with salt, ground coriander and pepper. Place the duck, fat-side up, on a sheet pan lined with a wire rack and refrigerate, uncovered, for 4 hours to overnight.
6 In a bowl, combine the orange juice, coconut aminos, honey, mustard, vinegar, gochujang, garlic and ginger. Whisk until well combined then set aside.
7 Remove the duck breasts from the fridge and pat them dry with paper towel. Transfer the duck to a cold pan, fat-side down, and place it over a medium heat. Weigh the duck breasts down with a kitchen weight or small pot to maintain even contact with the pan and cook, undisturbed, until golden brown, around 8 minutes. Flip and cook the other side while basting with the rendered fat, until the thickest part of each breast registers 135F for a medium centre, around 4 more minutes. Transfer the duck to a sheet pan lined with a wire rack and tent with foil to keep warm.
8 Pour all of the rendered fat through a sieve into a jar and reserve for future use. Return the pan to a medium heat and pour in the orange gochujang mixture. Cook the sauce, stirring and lifting any brown bits off the bottom off the pan, until it has reduced down by at least 1/2 in volume and can coat the back of a spoon, around 10 minutes. Add the cold butter and stir continuously until emulsified. Turn off the heat, add the sesame oil and stir through to combine. Taste the sauce for seasoning and adjust with salt and pepper as desired.
9 Thinly slice the duck breasts and fan them out over a bed of steamed jasmine rice. Spoon the orange gochujang sauce over of the duck and garnish with quick-pickled onions and chives. Serve immediately.
