Substitute good, stale bread crumbs (use microplane), fried with olive oil and broken up anchovies and you are getting kinda close. Check Luciano's, I may have seen it there.
Captain Caper I tied in a trip to the Glebe over the weekend and tried Il Negozio (most likely place to have bottarga) and also tried Whole Foods and Metro because they were on my route. None of them had it. I haven't made it to the Byward Market yet...
Captain Caper I may be going to La Bottega over the weekend and may even be passing by Il Negozio in the Glebe as well. I can check while I am out and about this weekend if you'd like...
On another note have you tried the Bagel Shop? They seem to have smoked salmon and some fancier stuff there - maybe they would have bottarga?...
RiceLover