Preheat your oven to 400°F (200°C).
In a small bowl, combine the lemon juice, olive oil, minced garlic, mixed herbs, salt, and pepper to form a marinade.
Place the chicken breast in a shallow dish and pour the marinade over it, ensuring it is well-coated.
Allow the chicken to marinate for at least 15-20 minutes. For deeper flavor, marinate in the fridge for up to 2 hours.
Meanwhile, prepare the cauliflower rice by pulsing cauliflower florets in a food processor until they resemble rice-like grains.
Heat a non-stick skillet over medium heat and add the cauliflower rice, seasoning lightly with salt and pepper. Sauté for 5-7 minutes until tender.
Place the marinated chicken breast on a baking sheet lined with parchment paper and roast in the preheated oven for 20-25 minutes or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).
Slice the roasted chicken and serve it over a bed of cauliflower rice, drizzling any remaining pan juices on top.