Place chopped bacon into Instant Pot and set to Sauté. Cook until bacon is browned and fat is rendered, about 5 minutes.
Place the lamb in a bowl. In another bowl, mix together salt, pepper, and flour, and pour over the lamb, tossing to coat. Add the lamb to the bacon and brown on all sides.
Pour in 1 cup of the beef broth, scraping up any browned bits from the bottom of the pot. Add the rest of the broth, and the bay leaves, rosemary, and thyme.
Close the Instant Pot and set to Seal. Cook on Manual High Pressure for 30 minutes. When the timer beeps, do a manual release of pressure.
Add the onion, mushrooms, carrots, and potatoes. Close the pot again, re-seal, and cook on Manual High Pressure for 10 minutes. When the timer beeps, let rest for 10 minutes, then do a manual release of pressure.
Season with salt and pepper to taste, then serve.
If desired, swap 1 cup of the beef broth for 1 cup beer or red wine