Add olive oil and butter to a large pan over medium heat.
Add onion and cook until translucent (4-5 min)
Add garlic, carrots, celery, frozen peas, thyme, and a pinch of salt. Cook down for a couple minutes.
Add orzo and broth, stir. Once simmering, cover and cook (5ish min)
Remove cover, add chicken and milk, stir. Cook another 4ish minutes
Stir in cheese and enjoy!