Make the slaw: Trim and peel the daikon, then shred on the large holes of a box grater. Transfer to a colander and squeeze dry. Whisk the lime juice and honey in a medium bowl. Add the cilantro and daikon; season with salt and pepper and toss to combine. Refrigerate the slaw until ready to serve.
Make the aioli: Combine the mayonnaise, sambal oelek and tomato paste in a small bowl. Grate in the garlic, season with salt and pepper and stir to combine.
Clean the crabs (if live): Cut off the front of each crab just behind the eyes and mouth using kitchen shears; remove any yellow matter from the inside with your fingers, if desired.
Grab one of the pointy ends of the top shell and peel it back to reveal the gills; cut out the gills and discard. Repeat on the other side.
Flip the crab over and pull back the small flap known as the apron. Use your fingers to pull it off.
Cook the crabs: Put the flour in a shallow dish and season with salt and pepper. Dredge the crabs in the seasoned flour, turning to coat both sides; shake off the excess flour and set aside. Melt the butter in a large skillet over medium heat and swirl the pan until the foaming stops. Add the crabs to the pan and cook until they start to turn an orange-red color, about 3 minutes per side. Remove to a paper towel-lined plate to drain and season immediately with salt.
Build your sandwich: Set your rolls cut-side down in the same pan and cook until golden. Slather the roll tops with some of the chile aioli. Sandwich a hot crab and a scoop of slaw on each roll.
Photograph by David Malosh
Recipe courtesy Jeff Mauro for Food Network Magazine