For the almond sauce, place the almond meal in a saucepan with 150ml water and a little of the oil and heat gently until the almond just starts to swell (this makes it easier to blend). Pour almond mixture into a blender and process to a smooth paste, then season to taste with brown rice vinegar and sea salt. With the blender running, add the egg yolks, then add the oil in a thin, steady stream until thick and creamy, check seasoning and set aside at room temperature.
Peel off the large outer leaves, then quarter the cauliflower, remove some of the core and steam on high for around 10 minutes or until a skewer goes into the stem easily. Set aside to cool to room temperature.
Heat the oven to as hot as you can get it. Place the steamed cauliflower in a roasting tray or a cast-iron pan and roast until it's dark golden brown (10-15 minutes; any charred parts are fine and add flavour).
Remove from the oven and dress simply with olive oil and lemon juice, and season with sea salt and black pepper.
Cover a plate with the almond sauce and sit the cauliflower on top, and scatter with almonds and mint.