Make the yoghurt sauce and place into the fridge to allow flavours to develop
Mix the Sriracha, cumin and olive oil together
Combine chicken and potatoes in a large bowl, pour over the marinade and mix through … allow to sit for at least 30 minutes at room temperature, or up to 8 hours in advance and store in the fridge - but remove 30 minutes before baking
Preheat oven to 220 degrees fan forced
Arrange chicken and potato in a large baking dish in a single layer (if the chicken and potato slightly overlap that is fine, but you don’t want the food sitting deeply on top of itself otherwise the chicken and potato won’t cook evenly)
Roast for 15 minutes
Whilst the chicken is cooking, in another bowl combine leek, lemon zest, oil and salt
Remove the baking dish from oven and toss the chicken and potatoes lightly
Scatter over the leek mixture ensuring you go to the edges as you want it to flavour the whole dish
Bake for a further 20 to 22 minutes until the chicken and potatoes are cooked through when tested with a skewer (the leek will look crispy and caramelized and that is what you want - I check the chicken at 20 minutes, and if necessary cook for a further 2 minutes - it is okay if the potatoes are still a little firm as you don’t want them mushy)
Pour over the lemon juice and allow the dish to rest for 10 minutes before serving
Serve the chicken and potatoes topped with the leeks, a large green salad and the yoghurt sauce on the side.