Step 1: Season the Beef - Add the beef stew meat directly to a 6 quart slow cooker. Sprinkle it with the salt, black pepper, garlic powder, and onion powder, then give the pieces a quick toss so the seasoning reaches as much of the meat as possible. You do not need to brown the beef first. That saves you time and keeps another skillet out of the sink, while the long cooking time still gives the beef plenty of opportunity to become tender.
Step 2: Add the Fresh Vegetables - Scatter the diced onion, sliced carrots, sliced celery, and minced garlic over the seasoned beef. These vegetables will slowly soften and release their flavor into the gravy as the beef cooks. There is no need to sauté anything first. Just spread everything reasonably evenly so the vegetables are not sitting in one big pile.
Step 3: Build the Savory Gravy - Spoon the condensed cream of mushroom soup over the beef and vegetables, then pour in the beef broth and Worcestershire sauce. Sprinkle the dried thyme over everything. Stir gently until the soup begins combining with the broth and the seasonings are distributed throughout the slow cooker. It might look a little loose right now, and that is exactly what you want because the filling still has several hours of cooking ahead.
Step 4: Let the Beef Cook Until Tender - Cover the slow cooker and cook everything on LOW for 7 to 8 hours or on HIGH for 4 to 5 hours. I prefer the LOW setting when the schedule allows because that long cooking time gives the stew meat plenty of opportunity to soften. You are looking for beef that is very tender and vegetables that can easily be pierced with a fork.
Step 5: Add the Peas - Once the beef is tender, stir in the frozen peas. Adding them toward the end keeps them from becoming overly soft during the long cooking time. They will warm quickly in the hot filling and give you those familiar little bites of sweetness you expect in a good pot pie.
Step 6: Thicken the Filling - In a small bowl, whisk together the cornstarch and cold water until the mixture is completely smooth. Pour that mixture into the slow cooker and stir it through the beef filling. Cover the slow cooker again, switch it to HIGH if necessary, and let the filling cook for about 10 to 15 minutes. You want the liquid to thicken into a rich gravy before the biscuit dough goes on top. This matters because biscuit dough can sink into a filling that is too thin.
Step 7: Mix the Cheddar Biscuit Dough - While the filling thickens, pour the Cheddar Bay biscuit mix into a medium bowl. Remember to keep the garlic herb seasoning packet aside because you will use it with the melted butter later. Add the cold water and shredded sharp cheddar to the biscuit mix, then stir only until everything comes together into a thick, shaggy dough. Stop as soon as the dry spots disappear. Too much stirring can make the biscuits denser.
Step 8: Spoon the Biscuits Over the Filling - Drop large spoonfuls of biscuit dough evenly over the hot beef mixture. Leave a little room between each mound rather than spreading the dough into one solid layer. Those small spaces allow steam to move around the biscuits, helping the centers cook instead of staying doughy.
Step 9: Cook the Biscuit Topping - Place a clean kitchen towel or several layers of paper towels beneath the slow cooker lid, making sure the material stays safely secured away from the heating element. This catches condensation that might otherwise drip back onto your biscuits. Cover and cook on HIGH for 45 to 60 minutes. Try not to lift the lid during the first 40 minutes because every peek releases heat and steam the biscuits need to cook.
Step 10: Check the Biscuit Centers - Once the biscuits look puffed and cooked, gently open one of the thickest portions and check the center. Slow cookers can vary quite a bit, so this is more reliable than judging by the surface alone. The tops will usually stay paler than oven baked biscuits, and that is normal. What matters is that the middle no longer looks wet or raw.
Step 11: Brush With Garlic Herb Butter - Stir the reserved garlic herb seasoning packet into the melted butter. Brush that mixture generously across the hot biscuits while everything is still warm. This is the moment the whole dinner really comes together. The butter melts into the biscuit tops, the garlic herb aroma wakes everything up, and suddenly everyone seems to find their way into the kitchen.
Step 12: Finish and Serve - Sprinkle chopped fresh parsley over the biscuits and serve the pot pie warm. Make sure each bowl gets a generous scoop of beef, vegetables, thick gravy, and at least one fluffy biscuit portion. Around our table, the biscuits tend to disappear first, so I have learned not to be shy when dividing them up.