Heat olive oil in a skillet, add the white and light green part of the onion chopped into slices and sauté for 1-2 minutes until the onion is soft. Keep the dark green ends aside.
Chop the cauliflower into florets and process it until it has the consistency of rice. You can use a food processor or a grater on medium thickness.
Add the cauliflower rice to the pan with the sautéd green onion. Stir over medium heat until the cauliflower is tender; any liquid it releases will reduce and turn lightly golden – this will take around 10 to 15 minutes, depending on the amount of cauliflower you have.
Add the cream cheese, salt, and ground black pepper. Stir over medium to low heat until all the ingredients are well combined.
Add the sour cream, buffalo sauce, ranch dressing, the dark green part of the green onion, and shredded mozzarella cheese. Mix well to combine.
Adjust salt and buffalo sauce to taste.
Once mozzarella has melted, remove from heat and serve warm.