Pat the pot roast dry and season all sides with salt and pepper
Optional: dredge the roast lightly in flour
Heat oil in a skillet over medium-high heat
Sear the roast on all sides until browned
Place sliced onions, carrots, and potatoes in the slow cooker
Set the seared roast on top of the vegetables
Add garlic, beef broth, and optional tomato paste or Worcestershire sauce
Add herbs such as thyme, rosemary, and bay leaves
Cover and cook on low for 8 to 10 hours or on high for 4 to 6 hours
Check that the roast is fork-tender before removing
Transfer the roast and vegetables to a serving platter
Skim excess fat from the cooking liquid if desired
Optional: thicken the liquid with cornstarch slurry for gravy
Slice or shred the roast and serve with the vegetables and gravy