Pre heat your oven to 400 degrees.
In a large bowl, toss together the cauliflower and oil. Mix the ranch mix together and add 2 Tbsp of it to the cauliflower, tossing to coat.
Spread onto a large, rimmed baking sheet in a single layer. Try to leave some space between then florets.
Cook for 15 mins. Then, stir and cook another 10-12 minutes, until golden brown.