1 pound fresh tuna
½ lemon
2 garlic cloves, peeled
½ fennel bulb
½ leek
½ red onion
1 tablespoon peppercorns
2 bay leaves, crushed
2 teaspoons kosher salt
Water
1cup good quality, extra virgin olive oil

Place all of the ingredients in a medium saucepan and cover with water.  Simmer for 15 minutes.  Let the tuna cool in the liquid.  Remove the fish, drain and place in a container that the tuna fits into snugly and cover with the olive oil. Store covered in the refrigerator for up to a week.