In a large skillet, sauté onion in olive oil for 2 minutes. Once onions are translucent add tomato, jalapeño (if using), brisket or carne seca and cook for another 2 to 3 minutes.
Meanwhile, in a medium bowl whisk eggs and then add them to skillet and cook for 2 to 3 minutes or until eggs are cooked thoroughly.
Serve with salsa of your choice and flour tortillas.
Notes
MAKE MACHACA WITH LEFTOVER SHREDDED BEEF:
Remember when we made these shredded beef brisket flautas? We were sure to double the recipe so that we can have plenty of brisket leftover to make this modern machaca recipe.