Bring 4 cups water to a boil in a medium saucepan, add the squares of meat and skim off any grayish foam that rises to the top during the first few minutes of boiling. Add the garlic, bay leaves, herbs, half of the onion and 1 teaspoon salt. Partially cover and simmer over medium to medium-low heat for an hour or so, until the meat is tender. If there is time, let it cool in the broth. Drain and discard all but the meat; then shred the meat into thin strands.
Combine the cooked meat, the remaining half of the onion, the radishes, chile, tomato and cilantro, and toss with the sour orange or lime juice and 1 ½ teaspoon salt. Taste and add more salt as desired.
As you’re ready to serve, build tacos: On a warm tortilla or lettuce leaf, spread a portion of the dzik in the middle, top with an avocado slice and a few leaves of cilantro and carry to your hungry guests.