Place meat in a soup pot or large, heavy pot along with the bay leaves, half an onion, 3 garlic cloves, 2 teaspoons salt and black peppercorns. Cover with water up to 2 inches above top of the meat. Bring to a boil over medium-high heat, reduce the heat to medium and simmer, partially covered, for 50 minutes to an hour, until the meat is thoroughly cooked and soft. Strain, reserving 2 cups of the meat cooking liquid. Once the meat has cooled enough to handle, shred it into pieces.
Heat the oil in a large casserole over medium-high heat, once hot add the onion. Cook for 4 to 5 minutes, stirring occasionally, until softened and it begins to brown. Pour in the salsa verde, and the reserved meat broth, once it comes to a simmer, add the swiss chard. Let it simmer for 2 to 3 minutes, and once the chard wilts, add the shredded beef. Let it all cook together for 5 more minutes. Taste for salt and add more if need be. Serve with refried beans garnished with crumbled queso and cilantro, and offer warm corn tortillas.
