Throw everything into the Instant Pot except for the mushrooms and carrots and stir until the ingredients are well incorporated.
Cook on high pressure for 15 minutes and release pressure quickly.
Add the carrots and mushrooms and cook for 2 mins at High Pressure and let it release pressure naturally.
If you want a thicker gravy, turn your Instant Pot on to Sauté, and once it's hot and the sauce is bubbling, make a cornstarch slurry and mix in, allowing it to thicken.
I don't usually like thickeners so I often use 1 cup of cauliflower which cooks down and thickens the gravy. If you're doing this, cook it along with the meat.
For the slow cooker, put everything into your slow cooker except the corn starch and water slurry, cook on low for 6-8 hours and on high for 4 hours until the meat is tender.
Slow Cooker Tips And Tricks
Add everything into the slow cooker except the corn starch and water slurry. In a pressure cooker, vegetables take longer to cook and break down. In contrast, slower cooking breaks down meats faster and makes them very tender. So you can put everything in at the same time
Increase water to about 1-1.5 cups. This is because you will lose some of the water to evaporation. In a pressure cooker, since it is totally sealed, you lose very little water to evaporation. This is why you always need to use less water when converting a recipe to pressure cooking.
How To Make This Low Carb
Use turnips or radishes instead of potatoes. If using turnips, cut them into 2-3 inch cubes. If using radishes, leave them whole.
Reduce or skip carrots. You can use frozen green beans instead. By using frozen beans, you will ensure they don't get overcooked in the time it takes for the other vegetables to cook.
You can also use frozen cauliflower along with the other vegetables.
Either skip the cornstarch slurry all together, and let the stew be a little thin, or use Xanthan Gum. Sprinkle about 1/2 teaspoon of xanthan gum to thicken the stew. Do not make a slurry with it! You will have a sticky, mucilaginous mess on your hands. Just turn the pot to Sauté, sprinkle the gum evenly, and then stir until thickened.
You can also add a cup or two of riced cauliflower in with the veggies. This will cook down and can sometimes help to thicken the gravy or sauce. You do not need to change cook times if you do this.