Bottarga is salted, cured fish roe that is traditionally sliced thinly or ground and sprinkled on seafood pasta dishes. It may sound weird and stinky, but trust me -- a little tossed in with spaghetti and clam sauce or sprinkled over fresh beans instantly transports you to the seaside.
Bottarga's flavor is the essence of the sea: Fishy, but not in a bad way, and very briny from the salt. If you happen to come across large roes in fish you catch, or if you buy some at the market, this is an excellent way to preserve them.
I typically use shad roe for this, but the Sardinians use mullet or tuna roe. You could also use halibut, herring, flounder, white seabass, weakfish or mackerel. You want small eggs (so no salmon or sturgeon!) and you want a nice ripe roe.
A ripe roe is one where you can see the eggs in the sac they come in, and that they are uniform in color. Overly watery roe is OK, but will take longer to cure. The roe on the far left of the picture is over-ripe. Unripe roe will not work -- you must be able to see the eggs; if they are too small, do something else with the roe.
Getting Started: Gather your roe and soak it in saltwater overnight. The next day, get a board or cookie sheet, some olive oil, lots of salt and paper towels.