Add carrots, celery and onions to the bottom of the slow cooker.

Mix flour, salt and pepper together in a small bowl.

(Optional) Trim any fat on the sides off of the roast and rinse with water.

Pat the beef dry with paper towels. Using your fingers, add flour mixture to cover the roast. (My roast this time was taller than I usually get it and it was tied for me. You can tie yours with kitchen twine if you want.)

Heat 1-2 tablespoons of oil in a large dutch oven on medium to medium high heat for  to 4 minutes. Add roast to heated pan and heat to sear for 2 to 4 minutes on each side. (Add more oil if needed and lower heat if necessary.) Use tongs to flip the roast and to hold the roast on its ends and sear for one minute.

Add the seared beef roast on top of the vegetables. Add french onion soup to the slow cooker. (If using condensed soup, add 1 cup of water to the slow cooker.)

Cook roast in slow cooker on low for 8 to 9 hours or high for 5 hours.

Serve with vegetables from the slow cooker and mashed potatoes or noodles.