Eggs
For my birthday we went with +Devour Barcelona Food Tours for a tour around the Gracia area of Barcelona. I think these food tours really are a great way to experience some local flavours as well as see some of the local areas - places you wouldn't normally find. We did one in Lisbon last year when we had a holiday there, and I guess I'm fortunate to have children who think this kind of tour is just heaven as well! In Barcelona part of the tour was to visit three different stalls in the market in Gracia, though not the egg stall, since they don't sell something you would normally eat without preparation.
My love of the markets in Barcelona is not just the general markets. Lots of places in the city have a food market where you can go to buy your fish, cheese, vegetables, meat, etc from small vendors who know what they are selling, and whose reputation depends on them knowing what they are talking about.
In many cities all of these functions have been subsumed into the supermarket, but there's not the same quality, and the profits from bulk aren't returned to the purchaser or the worker, they're retained by the owner of the supermarket.
After seeing this I think I now want to try an Ostrich egg Omelette!