Lengua in Mushroom Sauce

Method

1. Rinse the butcher-cleaned tongue and place in a large pot with covering water, quartered onion, bay leaves, peppercorns and salt. Bring to a boil, skim foam, then reduce to a gentle simmer. Keep it mostly covered with liquid.
2. Cover partly and simmer for 3–4 hours, turning occasionally and adding boiling water as needed. Test at the thick base: a skewer should slide in easily. Do not stop merely because the outside is cooked; the tongue needs time for connective tissue to soften.
3. Lift onto a board and allow to cool only until safe to handle with clean gloves or utensils. Peel away the thick outer skin while still warm, starting from the back, and trim rough tissue at the root. If the skin will not release, return to the simmer for longer.
4. Strain the broth and reserve 400 ml for the sauce. Slice the peeled tongue across the grain about 7–10 mm thick. For very neat slices, chill the peeled tongue and reserved broth promptly in shallow containers, then slice cold the following day.
5. Melt butter in a wide pan, soften the chopped sauce onion for 3 minutes, then cook mushrooms for 5–7 minutes until their liquid largely evaporates. Sprinkle flour over and stir for 1 minute. Add the measured broth gradually, stirring until smooth.
6. Add tongue slices and simmer gently for 5 minutes. Stir in cream, optional Worcestershire sauce and black pepper, then heat without a rapid boil. If using chilled tongue, make sure it reaches 74°C throughout. Taste before adding any more salt because the broth has reduced.
7. Serve with rice or mashed potato. Refrigerate leftovers within 2 hours and use within 3 days, reheating portions once to 74°C. Keep sauce slightly loose; it thickens when chilled and can be relaxed with a spoonful of water during reheating.