Set Instant Pot on Saute High.
Place butter in pot and allow to melt.
Salt and pepper meat and saute in batches until browned. Remove to bowl and continue until all is cooked.
Turn off pot and return meat to pot.
Add beef stock, tomato paste, Worcestershire, paprika, garlic and thyme,
Stir to combine.
Add onions, celery, potatoes and carrots.
Stir until well mixed.
Add bay leaf.
Cook on high pressure for 35 minutes.
When pot shuts off, cover vent with dish towel to avoid spattering and press quick release.
In a small bowl, whisk together cornstarch and water until well blended. Set aside.
Remove bay leaf and discard.
Add cornstarch mixture and stir until blended. Allow several minutes for sauce to thicken.
Salt and Pepper to taste and serve.