Many people are put off by the creamy texture of sea urchin roe, but fans consider it the most sensual of ingredients.
What is it? Despite its name, it isn't roe (male sea urchins, naturally, can't have such a thing); instead it's the sea urchin's reproductive organs.
What to look for: different types of sea urchins produce different coloured roe - it can be yellow, orange or reddish. Use a vendor with high turnover and pick roe that is evenly coloured, with no dark or grey spots. It should look moist, not wet, and each strip of roe should be well-defined.
How is it available? In shops, it's neatly laid out on small trays and protected by a plastic cover. Some countries hold sea urchin festivals, at which the tops of the urchins are removed and diners dig out the roe for themselves.
When is it in season? It depends on where the sea urchins come from. It can be harvested year-round, but is usually considered best when taken from cooler waters.
What else? Sea urchin roe is popular in Japan, where it's known as uni, and in France, where it's called oursin. It's also eaten in Korea and Mediterranean countries such as Spain and Italy. If you harvest sea urchins yourself, be wary of the sharp spines.