Heat 1 tablespoon olive oil over medium-high heat and toast rice and garlic, stirring frequently, for 30-60 seconds, or until lightly toasted.
Add onion and water and bring to a boil, then reduce heat to low, cover and cook for 20-30 minutes, or until rice has absorbed all water and is puffed up and fluffy.
Fluff rice with a fork, then stir in cheese and spinach. Whisk flour into heavy cream, then stir into rice. Cook until mixture has thickened slightly, 5-7 minutes.
Season with garlic powder, salt and pepper (as needed), then serve hot.