1. Put tongues, onion stuck with cloves, celery, bay leaf, peppercorns, and salt into a Dutch oven or kettle. Cover with water. Cover Dutch oven, bring to boiling, and cook until meat is tender, about 2 hours. Allow to cool in liquid.
2. Remove skin from cooled tongues, trim off roots, and slice meat into 1/2 inch slices. Strain stock in which meat was cooked and save, discarding onion, celery, and bay leaf. Return sliced meat to kettle.
3. For almond sauce, first prepare chilies. Put chilies, tomatoes, the whole almonds, 1/4 cup of the raisins, and the bread into an electric blender. Blend to a thick puree.
4. Heat lard in a skillet. Add the pureed mixture and cook about 5 minutes. Stir in tongue stock and remaining 1/4 cup raisins. Cook about 5 minutes, stirring constantly. Season to taste with salt and pepper.
5. Pour sauce over sliced meat in Dutch oven and simmer until meat is heated through.
6. Transfer meat and sauce to platter and garnish with slivered almonds.