1. To pickle the carrot,toss together quick pickled carrot ingredients in a bowl then set aside for 30 minutes. Grab handfuls of carrot and lightly squeeze out excess liquid then set aside.
2. Smush smashed avo ingredients with a fork until it's spreadable but still a bit chunky. Set aside.
3. To make the spinach dressing,whisk dressing ingredients in a medium bowl. Set aside.
4. To assemble,smear the base of each roll generously with avocado. Top with tomato and season with salt and pepper. Add spinach leaves to the dressing and toss,then pile onto each sandwich. Pile it up high and compress to keep building! Lay on 3 beetroot slices then shredded carrot and finally a pile of fluffy alfalfa. Smear the lid with avocado (as if you're buttering bread) then clamp the lid down firmly on the remaining sandwich. Devour.
Make ahead: Assemble the sandwich with the spinach undressed,then wrap tightly in cling film. Put dressing in a tiny jar. Refrigerate for up to 24 hours. Just before eating,flip the sandwich upside down. Remove the bread base and tomato slices,drizzle over dressing. Reassemble.
More vegetarian sandwiches from Nagi Maehashi