Heat a large frying pan on a medium high heat. Add a good glug of oil and cook beef, stirring to break it up until well browned.
Add tomato paste, smoked paprika and 4 tablespoons water. Simmer for a few minutes to bring all the flavours together. Taste and season generously with salt.
Warm tortillas according to the packet directions. I generally splash them with a little water and warm in a dry frying pan on a medium high heat for a minute or so on each side and then wrap them in foil and a clean tea towel to keep them warm.
Serve warm tortillas and cooked beef in the middle of the table with the lettuce and sour cream or avocado for everyone to help themselves.