Rinse the beef tongue under cold water
Trim off any excess fat or debris
Place the tongue in a large pot
Cover with water
Add salt, onion, garlic, bay leaves, and peppercorns if desired
Bring to a boil
Reduce to a simmer
Cook until tender, about 2 to 3 hours
Check tenderness with a fork
Remove the tongue from the pot
Let it cool slightly
Peel off the outer skin while still warm
Trim away any tough or discolored parts
Slice, chop, or shred as needed
Use in tacos, sandwiches, stews, or other dishes