In a microwave safe bowl, add the diced potatoes and stir in a pinch of salt.
Microwave for 6-8 minutes, gently giving the potatoes 1-2 stirs halfway between cooking (if you stir them too vigorously, you will release their starches and the potatoes will start sticking together as they cook)
Heat up a large skillet over medium heat and add a small swig of cooking oil.
Add in the potatoes and give a quick stir in the oil.
Add in the ground beef, making sure to break apart meat into smaller chunks as you cook it all the way through.
Add in salt & pepper to taste and serve inside warmed taco shells or on top of a salad.
Add toppings of choice.