Heat a medium skillet over medium heat and drizzle with avocado oil.
Add onion to pan and allow to cook for 2-3 minutes until soft but not brown.
Add garlic and cauliflower rice to pan and allow to cook for 7-10 minutes, stirring occasionally, until all moisture has evaporated and rice is beginning to brown.
Add lime juice and allow to cook for another 3-4 minutes until all moisture has been absorbed.
Remove pan from heat, fold in lime zest and cilantro, and salt and pepper to taste.
Serve immediately, refrigerate for up to 5 days, or portion and freeze for up to a month.