A recipe I’m following asks for a green meat radish. Where would be a good place to get one (I’m from the UK) or what could I substitute it with?
I'm in the US and I had never heard of a green meat radish. However, based on information I found on Specialty Produce, I would think you could substitute almost any regular variety of radish you find at your local grocer.
Excerpts from the linked page:
Green Meat radishes are easily distinguished by their shape and color. The swollen and elongated taproot is two-toned like several radish varieties, yet it is unique in its coloring. Its upper half near the stem end is lime green colored, and its tapered lower half is cream colored. It can be harvested when as small as five inches or as large as ten inches. Its thick skin covers a green to creamy white flesh which offers a crisp texture and a radish flavor that can vary from mild to hot depending upon growing conditions and maturity.
The spicy flavor and crisp texture of the Green Meat radish shines in fresh preparations. Slice thin and add to sandwiches, salads or wraps. Use to add a spicy accent to tacos, nachos, and Mexican soups. Slice lengthwise and pair with cream based dips or soft cheeses. Grate and serve as a condiment with sushi or sashimi or add to slaws to give them a spicy kick. In China Green Meat radishes are popularly pickled along with Sichuan peppers. Green Meat radish greens can be added to soups and stir-fries. To store, keep Green Meat radishes refrigerated and used within one to two weeks.
More interesting reading on the linked page, also.
Seeds are available in the UK if you want to grow your own, though that's only good if you want to wait a few months (my usual supplier of veg seed, Chiltern, doesn't have them).
From descriptions I've read, they're closer to the milder pink summer radishes in flavour than to the winter radishes (like mooli). So you're probably best just using normal radishes, toning down the quantity if you're worried about the overall effect being too peppery.
Try a specialty Asian food market, which you should be able to find in the closest metropolitan area to you. It is a similar to daikon, and that can be substituted with turnips or white radishes (for texture) and a small amount of horseradish (for spice).