Place the chuck roast in a large resealable freezer bag and rub both sides with the taco seasoning.
Squeeze the bag to mix up the ingredients, then remove excess air, seal, and freeze.
Thaw.
Place the contents of the bag in the pot. Put the lid on the pressure cooker and seal the vent, then set to cook on high pressure for 30 minutes. Allow the pot to naturally release for 10 minutes, then do a quick release to remove excess pressure.
When the meat is cooked through, remove and shred.
Serve over the top of tortilla chips and top with cheese and other toppings. Bake in the oven on a baking sheet to melt the cheese.
Thaw.
Place the contents of the bag in the bowl of the Crockpot. Cook on low for 7 to 8 hours or high for 4 to 5 hours.
Remove the meat and shred.
Serve over the top of tortilla chips and top with cheese and other toppings. Bake to melt the cheese.
Nacho Topping suggestions: