This sandwich is packed with flavour in the form of fragrant
tarragon salsa and beetroot pickle - both ideal foils for the
richness of the tongue. We've made our own brioche to get a
perfectly round small sandwich, but shop-bought brioche rolls would
also work well, or cut out rounds from a sliced brioche loaf.
1beef tongue (about 800gm; see note)2onions, 1 unpeeled and quartered1peeled and sliced into thick rounds3garlic cloves, unpeeled, bruised3thyme sprigs1fresh bay leafOlive oil, for drizzlingFrisée, to serveBrioche375 gmplain flour2 tspcaster sugar1½ tspdried yeast160 ml (2/3 cup)lukewarm milk5egg yolks, at room temperature150 gmbutter, diced and softened, plus extra for greasingBeetroot pickle150 mlred wine vinegar50 mlred wine2 tbspcaster sugar2beetroot, peeled and thinly sliced into rounds on a mandolinTarragon salsa1/3 cupfirmly packed tarragon1/3 cupflat-leaf parsley2 tspcapers in vinegar, drained 1garlic clove, coarsely chopped1 tspDijon mustard120 mlolive oil
Combine tongue, quartered onion, garlic, thyme and bay leaf in a large saucepan, cover with plenty of cold water, season generously with sea salt and bring to the boil over high heat. Reduce heat to medium, cover and simmer until tongue is very tender when pierced with a skewer (2½-2¾ hours). Drain (discard onion, garlic and herbs) and, when tongue is cool enough to handle, peel (discard skin) and refrigerate tongue in an airtight container for up to 3 days.
For brioche, combine flour, sugar, yeast and 1 tsp salt in an electric mixer fitted with a dough hook, then add milk and egg yolks, and mix until combined. With mixer on high speed, gradually add butter, kneading until incorporated before adding more. Knead until shiny and elastic (5-6 minutes). Transfer to a buttered bowl, cover with plastic wrap and stand in a warm place until doubled in size (1-1½ hours). Preheat oven to 180C and butter six 7cm-high, 6.5cm-diameter ring moulds and place on a baking tray lined with baking paper. Knock back dough, roll into 6 balls and place in moulds. Cover with plastic wrap and stand in a warm place until risen by half (30-40 minutes). Remove plastic wrap, place baking paper over moulds, then a heavy baking tray and bake until brioche rolls are golden brown and a skewer inserted withdraws clean (10-15 minutes). Cool, then store in an airtight container until required.
For beetroot pickle, bring vinegar, wine, sugar and 60ml water to the boil in a small saucepan, season to taste, then add beetroot and cool to room temperature.
For tarragon salsa, process herbs, capers, garlic and mustard in a small food processor until finely chopped, then add oil, process to a purée and season to taste.
Heat a char-grill pan to high. Drizzle onion rounds with oil, season to taste and grill, turning once, until browned (1-2 minutes each side). Thickly slice tongue across the grain (you won’t need it all), drizzle with oil, season to taste and grill, turning once, to warm through (30 seconds to 1 minute each side).
To serve, trim tops and bases of brioche, then slice each into three. Toast slices lightly under a hot grill, then top half with tongue, onion, drained beetroot pickle and a drizzle of tarragon salsa. Season to taste, top with frisée, sandwich with remaining brioche slices and serve.