Pat the roast dry; season all sides with salt and pepper.
Heat olive oil in a skillet over medium-high. Sear roast 3–4 minutes per side.
Layer potatoes, carrots, onion, celery, and garlic in the slow cooker.
Whisk broth, Worcestershire, tomato paste, rosemary, and thyme. Pour over the vegetables.
Set roast on top. Cover and cook on Low 8–9 hours or High 4–5 hours.
Transfer beef and vegetables to a platter. Tent with foil to keep warm.
Skim fat from cooking juices. Bring 2 cups to a simmer in a saucepan.
Stir cornstarch with cold water. Whisk into juices and simmer until thickened.
Slice or shred the roast. Serve with vegetables and plenty of gravy.
Notes
Variation: Add 1/2 cup dry red wine with the broth for a deeper, richer gravy. Leftovers keep 4 days refrigerated; reheat gently with a splash of broth.This recipe is an original creation inspired by classic Easy Slow Cooker Pot Roast Recipe flavors. All ingredient ratios and instructions are independently developed.