Season and dredge the beef: Pat the beef dry. Season generously with salt and pepper. Toss with the flour to lightly coat. This helps browning and later thickening.
Sear (optional, but do it): Heat oil in a skillet over medium-high. Brown the beef in batches, 2–3 minutes per side. Don’t crowd the pan. Transfer to the crockpot. Yes, this step matters—flavor is built here.
Layer the veggies: Add onions, carrots, and potatoes to the slow cooker. Place the seared beef on top so the veggies don’t turn to mush under it.
Mix the braising liquid: Whisk beef broth, tomato paste, Worcestershire, soy sauce, thyme, rosemary, paprika, garlic, and a pinch of salt/pepper. Pour over the beef and veggies. Tuck in bay leaves.
Cook low and slow: Cover and cook on Low for 8–9 hours or High for 4–5 hours, until the beef shreds with a fork and potatoes are tender.
Adjust texture: If you want thicker gravy, whisk cornstarch with water and stir into the stew. Cook on High for 15–20 minutes more until glossy and thickened.
Finish with peas: Stir in frozen peas for color and a pop of sweetness. Fish out the bay leaves. Taste and adjust seasoning with salt and pepper.
Serve: Ladle into bowls, sprinkle with chopped parsley, and try not to inhale it in 60 seconds.