Pat the beef stew meat dry with paper towels to help seasonings stick and reduce moisture.
Place beef in an even layer in the slow cooker.
Sprinkle onion powder, garlic powder, and seasoned salt over the beef, rubbing lightly to coat.
Scatter sliced butter evenly over the seasoned beef.
Add chopped fresh garlic on top of the beef and butter.
Tuck halved baby yellow potatoes around and on top of the beef.
Cover and cook on low for 6 to 8 hours, checking for tenderness after 6 hours.
When done, gently stir to coat meat and potatoes with butter and juices.
Adjust seasoning with additional seasoned salt or black pepper if needed.
Serve hot, optionally garnished with extra butter or fresh parsley.