Pat beef chuck roast dry with a paper towel and place in a crock pot.

Sprinkle taco seasoning on top of the beef and rub it into the beef with your fingers, kind of like massaging it in.

Add in the jalapeno (if you want it more spicy leave in the seeds, if you like it less spicy seed the jalapeno before putting it in.) and then pour cola over the meat - you want it about just to the top of the beef.

Squeeze in lime juice and turn the heat on low and cook for 6 hours (alternatively you could cook it on high for 3 hours).

After 6 hours remove the beef and with two forks shred the beef and enjoy!

For the tostadas simply pile on shredded beef, lettuce, guacamole, sour cream and shredded cheese.