Place stew beef and cubed pork in large dutch oven, add chopped onions, chopped garlic cloves, both cans of tomatoes, salt and cumin; add enough water just to cover all ingredients.
Place on high heat and bring to a boil. Turn heat down to medium and simmer about 4 hours.
After 4 hours turn heat back up and reduce the liquid, but careful not to let burn, stir often.
When liquid is reduced stir while tearing and shredding meat or you can use a hand mixer to shred meat.
After meat is done remove from heat, heat tortilla on direct burner over fire about 3 sec on each side. I also do this on my electric burner. Or you can heat the tortilla's however you wish. Place couple spoons of meat on tortilla add your favorite toppings.