This site will give you the information you need:

Here is a link that might be useful: perilla

Thank you Daisy; the recipes aren't what I expected. Have you ever used this herb?

Yes, I've grown it and eaten it, but I'm not into Japanese food, so I've only used it as a substitute for spinach, or in salads, stirfries, quiche etc. I grew it mainly for its colourful foliage, but like the amaranth it attracted grasshoppers to the garden, so I got rid of it pretty quick-smart.