Prepare chicken by mixing all lemon juice, olive oil, garlic, oregano, salt, and pepper in a large bowl. Add chicken breasts to bowl and let marinade for 30 minutes in fridge.
Prepare pasta according to directions on box. Drain and set aside.
For the cauliflower sauce, heat a large dutch oven or sauce pan over high heat. Add butter and garlic. Cook for 2-3 minutes or until very fragrant.
Add cauliflower and water to saucepan with butter and garlic and bring to a boil. Once boiling, reduce heat to medium and let simmer 12-15 minutes or until cauliflower is fork tender.
While cauliflower is boiling, turn on grill to medium-high heat to cook chicken. Spray grill with nonstick spray. Because the breasts are so thin, they will cook very fast.
Place chicken on grill and cook about 4 minutes on each side, or until internal temperature reaches 165F. Take chicken off grill and let rest.
Once cauliflower is cooked, add all ingredients to a blender and then add the juice of one lemon. Blend until completely smooth.
Add pasta to sauce pan, then pour the cauliflower sauce on top. Mix until well combined.
Slice up chicken in strips and add to pasta, then top with fresh parsley! Enjoy!