Pickled Beef Tongue, Cauliflower Purée, and Pickled Mustard Seeds
For the Pickled Mustard Seeds:
Combine the mustard seeds, vinegar, garlic, and both kinds of chilies in a large sauce pot; bring to a boil. Remove from heat and pour into a 1 quart container. Seal and let sit for 7 days.
For the Pickled Beef Tongue:
Combine the water, vinegar, mustard seeds, coriander seeds, chili flakes, peppercorns, and salt in a sealed container with the tongue. Refrigerate for 2 days. Preheat the oven to 325 F. Put the tongue, with its spices and liquid, into a Dutch oven. Cook in the preheated oven for 6 to 7 hours, or until tender. Remove the tongue from the liquid and cut into ½-inch slices.
For the Cauliflower Purée:
In a large sauce pan, sauté the onion with 3 tablespoons of butter until onions are translucent. Add the cauliflower and sauté until tender. Put the onions and cauliflower in a blender and puree with remaining 4 tablespoons of butter, until smooth. Reserve.
To Assemble and Serve:
Place 2 tablespoons of Cauliflower Purée on a plate. Fan out 3 slices of warm Pickled Beef Tongue on top. Top the tongue with a teaspoon drizzle of Pickled Mustard Seeds.