Preheat oven to 400 degrees.
Cut the cauliflower into steaks and brush with olive oil. Season with salt, pepper and onion powder.
Lay strips of bacon on a baking sheet under parchment paper (easier clean up) and throw into the oven for 10-15 minutes or until desired crispiness.
In an oven-safe pan over medium heat, add some olive oil (or neutral oil) and sear the cauliflower steaks for a few minutes on each side, or until golden. Transfer to the oven to finish roasting for 10 minutes.
In a sauce pan over low-medium heat, add butter and stir until melted. Add in flour and whisk for 2-3 minutes (this is your roux). Gradually stir in milk and the sauce will thicken up over the next few minutes. If the consistency is too thick you can add some more milk. If it’s too thin you can either simmer a bit longer on low heat or you can make more roux (butter & flour) in a separate sauce pan and add that to your sauce. Remove from heat, add in seasonings and hot sauce, grated cheese and stir. It should be creamy and luxurious.
Assemble: roasted cauliflower steaks, drizzle with cheesy sauce, top with crumbled bacon, chives and microgreens (optional).