Preheat oven to 375 degrees Fahrenheit and line baking sheet with silpat mat. If you don't have a mat, just grease your pan with a little extra olive oil. 

Trim any green, inedible leaves from cauliflower and carefully trim any excess stem. Try to leave most of the stem intact as this helps hold the cauliflower steaks together. 

Cut cauliflower in half down the center. Then cut into thick 1 1/2" slices moving outwards from the center. We usually get about 3-4  "steaks" per head of cauliflower. The slices from the center of the head of the cauliflower are the best "steaks" as the stem helps hold the florets together in one piece. We slice up the extra pieces and add them to the sheet pan to roast as well. 

Arrange sliced cauliflower onto your baking sheet and brush with olive oil on both sides. Sprinkle with salt, pepper, and other seasonings as desired. 

Bake for 20-25 minutes and use a spatula to lift edge of cauliflower steak. Flip when bottom is starting to turn golden brown. 

Bake another 10-15 minutes on the second side or until cauliflower is tender when pierced with a fork. 

Serve with pesto.