Preheat a large Dutch oven over medium-high heat. Add 1 tablespoon of olive oil and let it heat until shimmering. Season the beef chuck roast with salt and pepper and sear until brown, about 12 minutes.

In the same Dutch oven, add another tablespoon of olive oil and the sliced yellow onions. Cook over medium heat until translucent, about 5 minutes. Reduce heat to low and caramelize slowly for 20 minutes.

Once caramelized, stir in the minced garlic and maple syrup or brown sugar. Cook for an additional 7-8 minutes.

Sprinkle all-purpose flour over the onion mixture, stirring for 1 minute. Pour in the red wine and scrape up browned bits. Add beef broth and stir until smooth.

Return the seared beef roast to the pot, partially submerged in liquid. Add thyme and bay leaves. Bring to a simmer, cover, and transfer to an oven preheated to 300°F.

Cook for 3 to 4 hours, checking for tenderness halfway through.

Let the pot roast rest for 15 minutes before shredding and serving with the caramelized onion mixture.