Roasted Sweet Beet Relish

Preheat the oven to 350°F. For the tomato purée, halve the tomatoes and place them, skin side down, on a baking sheet. Sprinkle with the salt, garlic, and olive oil. Roast for 1 hour on the bottom shelf of the oven, then remove. Press through a sieve or pass through a food mill to remove the skins and seeds – you’ll end up with about 1 1/4 cups of intensely flavored purée.
Meanwhile, put the beets into a baking dish and drizzle with a little olive oil. Roast, above the tomatoes, for 1 to 1 1/2 hours (longer if necessary), until the skins are blistered, blackened, and loosened. Let cool a little before peeling. You’ll find the skins will slide off easily. Coarsely grate the beets (a food processor makes this job easy).
Put the sugar, vinegars, onion, and horseradish into a large saucepan; bring to a boil and cook for 5 minutes. Stir in the tomato purée and cook for a couple minutes more. Finally, add the grated beets and cook for about 10 minutes, until thickened. Transfer to sterilized jars and seal with vinegar-proof lids (see pp. 21–22). Use within 1 year. Refrigerate once opened.
It’s easy to pickle horseradish root. Just grate enough fresh root to fill a jam jar, sprinkle with 1 teaspoon of salt and 1 teaspoon of sugar, top up with cider vinegar, and seal with a lid. Use in sauces, dressings, and soups, and serve with roast beef.