Preheat oven to 300 F.

Heat olive oil in a large Dutch oven over medium-high heat.  Season roast with salt and pepper, then sear the meat until browned on both sides (about 1-2 minutes per side).  Remove from heat.

Stir the Coke and onion soup mix together in a bowl, then whisk in the chili sauce.

Pour the Coke mixture over the chuck roast, scraping up any brown bits on the bottom of the pot.  Cover and bake for 1 hour.

Add the onions and carrots to the roast, cover and continue baking for another 2-3 hours, until meat and vegetables are fork tender.

Serve with mashed potatoes, hot buttered egg noodles or crusty bread to absorb the sauce.