Cook the bacon until crisp, drain & set aside.
Add 2 tablespoons of bacon grease to the liner of the Instant Pot. Using the sauté function, brown the potatoes on all sides, 5-10 minutes. (Don't use 'high' here, the grease will get too hot & the potatoes will stick to the pot.)
Remove the potatoes from the bacon grease with a slotted spoon. Add the water or stock to the pot to deglaze. Use a wooden spoon to stir up all the little brown bits from the bottom of the pot.
Turn off the sauté function. Add the thighs to the liquid, gently pushing them down to ensure each piece of chicken is submerged or touching the liquid. Add the potatoes evenly over the top.
Add the lid to the Instant Pot. Turn the pressure cooker on high & set the timer for 12 minutes. After cooking time is complete, let the cooker do a natural release for 15 minutes, then manually release the remaining steam.
Use a slotted spoon to set the potatoes in an even layer on the bottom of the serving dish. Set the thighs on top of the potatoes & discard the liquid in the pot. Crush the bacon and sprinkle evenly over the thighs, then cover the chicken evenly with the shredded cheese.
Tightly cover the serving dish with foil. Let it sit for 10 minutes so the cheese will melt into yummy goodness. Serve with a green salad. Watch your family devour the whole thing.