Heat a lidded skillet with oil over medium heat
Add the onion and cook for 5 minutes
Add the garlic and cook for 3 more minutes
Stir in the spinach and cauliflower rice and cook until the spinach wilts, about 2 minutes
Add the remaining ingredients except the cheeses and bring to a boil
Gently press the mixture so the orzo is mostly submerged, cover, and simmer for 10-12 minutes, stirring once, until the orzo is tender
Remove from heat and fold in the cheeses
