Combine all ingredients for the chicken marinade in a large bowl and whisk to combine. Add the chicken to the bowl and stir to coat. Set aside in fridge for 20 minutes-2 hours.
Combine all ingredients for the pickled red onions in a small bowl. Stir to combine. Set aside for at least 20 minutes (but longer is better!). You can store the pickled onions on the counter for 3 days to use throughout the week.
Cook the rice (or grain of choice) according to package instructions.
Prep the other ingredients by chopping the tomatoes and cucumber. Set aside.
Stir together all ingredients for the Lemon Dill Yogurt, set aside in fridge for at least 20 minutes for the flavors to combine.
Heat a large cast-iron pan or non-stick skillet over medium heat for 5 minutes. Add 2 tbsp of avocado oil and continue to heat for another minute.
Using tongs, add the marinated chicken to the pan, cooking & rotating with tongs until cooked through and has a crust, about 8-10 minutes.
Assemble the bowl by layering the greens, the grain, the cooked chicken, the veggies and pickled onions and top with the Lemon Dill Sauce and crumbled feta.