Combine buttermilk, hot sauce and salt to taste in a mixing bowl. Marinate cauliflower florets in buttermilk for 2 to 3 hours.
Combine corn meal, all-purpose flour, ½ teaspoon paprika, ¼ teaspoon black pepper and salt to taste in another bowl. Once cauliflower is marinated, drain the florets and transfer to flour mixture. Coat florets with flour and shake off excess flour.
Heat oil for frying in a frying pan until ready to fry. Fry cauliflower florets in 3-4 batches until golden brown. Transfer to paper lined plate to drain excess oil.
To assemble rolls: Toast the hot dog buns on a griddle with butter. Combine mayonnaise and yogurt in a big mixing bowl and whisk to make it smooth. Add red pepper, celery, onion, lemon juice, ½ teaspoon paprika, ¼ teaspoon black pepper and celery salt. Stir to combine. Once excess oil is gone from cauliflower florets, add warm florets to mayo mixture and stir to combine. If you are not ready to serve roll immediately then wait to add florets until you are ready to serve them. Open the top slit of buns and divide the florets filling among four buns. Serve immediately.
Recipe by Lovely Masala at http://www.lovelymasala.com/cauliflower-rolls/