To a large ziploc bag, add the flour, salt and pepper and shake to mix.
Cut stewing beef into 1" cubes and then toss into flour mixture bag. Shake to coat.
Add olive oil to a large non-stick skillet over medium high heat and then add beef and flour mixture (including any excess flour).
Brown the beef then add the chopped onion and garlic. Cook until onion is soft.
Pour the beef, garlic and onion mixture into the bottom of a slow cooker with the rosemary, thyme, and bay leaf.
Top with the potatoes, carrots, celery, broth, onion soup mix, and Worcestershire sauce. Stir to combine.
Cover and cook on LOW for 6-8 hours or HIGH for 4-6 hours. Stir in frozen peas 15-30 minutes before serving.
Use a marbled cut of beef for the most tender stew, like chuck. Cut into 1" cubes. If you don't have beef broth, use 3 cups water + 2 beef bouillon cubes or 1-2 tsp beef bouillon granules.Store leftovers in an airtight container in the fridge for 3-4 days.Stew will freeze really well. Add to plastic containers, leaving room at the top to allow for expansion, and freeze for up to 4 months.