Preheat a large saute pan over medium-high heat.
Place the flour in a shallow bowl and coat the beef, making sure that the flour adheres to the beef and any excess falls off.
Add the canola oil to the saute pan once hot and then add the beef. Brown on all sides, for 10-15 minutes total, flipping carefully after 7-8 minutes. Remove the roast from the pan, keeping the stove on.
Add the onion, carrots and celery. Sprinkle with salt and black pepper and saute until cooked through and tender, about 8 minutes. Add the garlic and cook for an additional minute. Remove the pan from heat.
Heat your slow cooker to low (if you are cooking for 7-8 hours) or high (if you are cooking for 3-4 hours). Add the sautéed veggies to the slow cooker. Add the tomatoes, beef broth, red wine, thyme, rosemary, oregano, parsley and granulated sugar. Sprinkle with salt and pepper. Stir to combine. Add the beef to the slow cooker and cover. Cook for 7-8 hours on low or 3-4 hours on high.
When the beef has cooked, remove the beef from the slow cooker and cover with foil, leaving the slow cooker on. Increase the setting to high, if not set to it already. Add the cornstarch and water mixture to the slow cooker with the sauce and whisk to combine. Continue to whisk until the sauce has thickened substantially, about 2-3 minutes. If you find that the gravy isn't thick enough for you, feel free to add more cornstarch mixture until you reach the consistency you desire.
Serve the beef with the gravy and enjoy!