For the chicken: Blend the turmeric and some salt with the yogurt in a large bowl and add the chicken. Toss to coat and marinate chicken for at least 10 minutes or up to 2 hours (in the fridge).
Preheat a grill or grill pan over medium-high heat. Remove the chicken from the marinade and grill for a few minutes on each side, until cooked through.
For the vegetables: Drizzle olive oil on the onion, tomato and lemon and season with salt. Grill all until a bit charred on each side.
For the tzatziki: Incorporate the yogurt, dill, mint, lemon juice and cucumbers. Season with salt and set aside.
To serve, drizzle the chicken with garlic herb oil and spoon a scoop or two of tzatziki directly on top. Plate each dish with a few pieces of grilled veggies and, before serving, squeeze 1 grilled lemon half over the chicken and sprinkle with oregano.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.