Marinade the chicken for at least 15 minutes, but can marinade the chicken over night.
Melt butter in skillet over medium-high heat and add the fresh oregano, thyme, and rosemary. Add chicken and cook 4-5 minutes on each side until no longer pink. Remove thighs from pan and set aside, leave the remaining juices in the skillet.
Add garlic and onions to the pan and cook until fragrant, about 1-2 minutes. Add the riced cauliflower and mix everything together. Stir in chicken stock, parsley, lemon juice, and lemon zest. Cook 2-3 minutes to reduce liquid and add the parmesan.
Add chicken thighs to the top of cauliflower rice and allow to re-heat if necessary. Serve immediately.