Preheat the oven to 425°F / 220°C. Put 8 pork sausages and 1 tablespoon of sunflower oil in an 8 × 12in / 20 × 30cm roasting pan and roast for 15 minutes.
Meanwhile, mix 100g of all-purpose flour and ½ teaspoon of English mustard powder. Beat in 1 egg, then gradually whisk in 300ml of milk until smooth. Stir in the leaves of 3 thyme sprigs and season with salt and pepper.
Pour the batter into the hot fat around the sausages. Bake for about 40 minutes, until risen and set and a knife in the center comes out clean.
