Heat a large skillet over medium-high heat. Add olive oil, and once hot, add chicken. Cook until no longer pink - about 4-5 minutes. Drain excess liquid and set chicken aside in a separate bowl.
To the same skillet, add butter. Once melted add onion and cook for 3-4 minutes or until just beginning to soften. Add in zucchini and cook for another 3-4 minutes, then add garlic and stir. After about a minute, add chicken back in to skillet.
Add in parsley, thyme, salt, and pepper and toss to coat. Then add in rice, chicken stock, lemon juice, and parmesan cheese. Mix until all combined.
Bring to a simmer. Once simmering, reduce heat to medium and cover with lid. Let cook for 15-20 minutes or until all of the rice is absorbed.
Turn off heat. Sprinkle with cheddar cheese and place lid back on for 5 minutes to let cheese melt.
Sprinkle with parsley and serve! Enjoy