Warm Picnic Burritos

This is another family favorite.  It is due in part to our secret chimichuri sauce, but still a stellar meal. In addition to he chimichuri, we also add sliced scallions. Skirt steak is a bit pricey, so we use any inexpensive roast.(bottom round this time)  The long cooking time makes it tender and when I shred the beef, I can remove any fat, connective tissue etc, that I don't want to eat. The Serrano does not make it hot at all; the long cooking time mellows the heat and you mostly taste the pepper's fruit as opposed to the fire.

Warm Picnic Burritos ("Burritos De Machaca")
 2 T  Maggi sauce* or 1 tablespoon soy sauce,plus 1tablespoon Worcestershire sauce
2 T  water
4 T  fresh lime juice
3    garlic cloves,minced
1    serrano chile,stemmed,seeded, and minced
Salt and freshly ground black pepper
1/2 c  olive oil
1    (2 to 3-pound) skirt steak trimmed and cut into pieces
3 T  vegetable or olive oil
1 1/2 c  diced onion
1 c  diced red bell pepper
3    garlic cloves,minced
2    serrano chiles,stemmed,seeded, and minced
1 c  beef broth
1 cn diced tomatoes with juice
1/2 t  dried oregano
Salt and freshly ground black pepper
12    (6-inch) flour tortillas
           Lime wedges,for serving
[Note: Hodges: Maggi sauce is a popular seasoning in Mexico that can
be found in Latin markets  ]
Combine the Maggi sauce, water, lime juice, garlic, chile, salt, and
pepper, to taste, in a medium-size bowl. Slowly add the 1/2 cup of
olive oil, whisking constantly.
Add the beef to the marinade, making sure each piece is coated with the
mixture. Transfer the meat and the marinade to a quart-size freezer bag.
Seal and refrigerate for at least 8 hours or preferably overnight.
Allow the meat to come to room temperature before cooking, about 30
minutes. Remove the meat from the marinade and pat dry with paper
towels. Discard the marinade.
In a large heavy pot, heat the vegetable oil over medium-high heat.
Sear the meat on all sides, a few pieces at a time, about 4 minutes per
side. Transfer the browned meat to a platter and set aside.
Add the onions, peppers, garlic, and chiles to the hot pan. Saute for 5
minutes, then add the beef broth, tomatoes, oregano, salt and pepper,
to taste. Mix well, then return the meat to the pan. Bring to a boil,
reduce the heat, cover, and simmer slowly until the meat is very tender,
about 2 hours. Transfer the meat to a cutting board and allow to rest
until cool enough to handle, about 15 minutes. Continue to cook the
onion mixture until most of the liquid has evaporated, about 10 minutes.

Using your fingers or 2 forks, shred the meat into 2-inch-long pieces.
Return the shredded meat to the pot, stir to combine, and cook until
meat is very hot, about 3 minutes.
Warm the tortillas over a burner or in a dry skillet over medium heat
for 20 seconds. Put about 2 tablespoons of the meat mixture in the
center of each tortilla, and roll into a thin burrito. Arrange them on
a serving platter and garnish with lime wedges.