Shiso is one of the most distinctive of herbs: once tasted, it's hard to forget its strong flavour and scent. The plant is part of the mint family and, like mint, it has a refreshing, palate-cleansing flavour. The wide leaves, which can be green or purple, have jagged edges, and the pretty, tiny, white or lavender shiso flowers are also edible.
As you'd expect from the name, shiso is popular in Japan. It's eaten fresh or dried, and the leaves can also be salted and preserved. Purple shiso is what gives umeboshi (preserved ume, or green apricot) its pink colour. You've probably seen the whole leaves on sashimi platters, where it's used as an edible garnish (I like to wrap a slice of fish in it before dipping it in soy sauce). The leaves can also be sliced - usually as chiffonade - but as the cut edges darken, this should be done just before serving.
One of my favourite Japanese appetisers is made by putting salted squid guts and shiso chiffonade on small slices of cream cheese. The bland richness of the cream cheese is the perfect foil for the two strongly flavoured toppings.
I also like it as a topping for mentaiko (preserved fish roe) pasta. Start by boiling some spaghetti. While the pasta is cooking, fry a minced shallot in a little oil until soft, then add some white wine to the pan. Cook until it's reduced to a syrupy glaze, then add mentaiko that's been taken out of the egg sac. Whisk in a little cream. When the pasta is cooked, drain it and add it to the skillet, then stir it to coat it with the mentaiko sauce. Transfer to a shallow bowl, top with shiso chiffonade and serve.