Prep the cauliflower rice, peas, and carrots: If using fresh cauliflower, refer to instructions for making cauliflower rice. For this recipe, I use frozen cauliflower. Microwave the bag for slightly more than half the recommended time. This helps to avoid burning your hands when squeezing out the excess water. Cut the top or a corner of the bag and squeeze out every bit of water you can. The rice may clump together, which is desirable. Set aside when done.
Cook the peas and carrots from frozen, just enough to remove the ice. Drain them and place in a bowl with the diced onions and green onions. Prepare a slurry using the soy sauce and oyster sauce. (See notes for alternatives or questions.)
Cook the fried rice: In a pan or wok on medium heat, add a little vegetable oil and scramble the beaten egg. Remove the scrambled egg from the pan and set aside.
Add a little more oil to the pan, then add the diced onion, green onion, minced garlic, peas, and carrots. Season with salt and pepper to taste (starting with about 1/4 teaspoon each).
Once the diced onion is translucent, remove all the veggies from the pan.
Turn the heat up to medium-high, add a little oil, and place the cauliflower rice in the pan. Break apart any clumps and cook for about 1 minute. Add the slurry of soy sauce and oyster sauce, quickly mixing it into the rice before it evaporates from the heat. Ensure the rice is evenly coated.
Lower the heat and toss the scrambled egg and cooked veggies back into the pan. Mix well and cook for about a minute. Remove from heat and serve.