Place the brisket in an oven safe dish, dribble about a 1/4 cup of water over the brisket. Cover the dish with aluminum foil and place in an oven heated to 350º for about 10 minutes.
Meanwhile, wrap your soft tortillas in foil, when brisket reaches 10 minutes, place foil packet in oven, next to brisket and cook for another 10 minutes.
While these are heating, shred about 3/4 cup of Monterey Jack cheese and 3/4 cup cheddar cheese.
Shred about 1 cup of iceberg lettuce.
Once brisket and tortillas are warm, remove from oven.
Lay tortilla flat and spoon brisket, in a straight line, down the center of the tortilla.
Add shredded cheese. I put the cheese next to the brisket, so it will melt slightly.
Add a tablespoon or so of fresh salsa, top with lettuce. Top with a teaspoon of sour cream.