Preheat your oven to 400°F. Line a large baking sheet with parchment paper, and set aside.
Cut your cauliflower into florets. The easiest way to do this is to quarter the cauliflower head and cut out the core. Then, simply separate the florets from each other.
Place your cauliflower on your baking sheet. Evenly drizzle olive oil, salt, and (if using) garlic and lemon juice over the cauliflower. Toss to coat all the florets with the toppings and spread into a single layer on your baking sheet.
Bake in the center of your preheated 400°F oven for 20 to 25 minutes. Half way through the bake time, take your cauliflower out of the oven and toss so they brown evenly. Bake until the cauliflower is golden brown and fork tender.