Season the beef cubes with salt and pepper. In a large skillet, heat the olive oil over medium-high heat. Brown the beef in batches, about 5 minutes per batch, then transfer to the slow cooker.
In the same skillet, add the chopped onion and minced garlic. Sauté for 2-3 minutes until softened, then add to the slow cooker.
Add the sliced carrots, diced potatoes, beef broth, Worcestershire sauce, dried thyme, and bay leaf to the slow cooker. Stir to combine.
Cover and cook on low for 7-8 hours or on high for 4-5 hours, until the beef is tender.
About 30 minutes before serving, stir in the frozen peas. Remove the bay leaf before serving.