Begin by prepping your ingredients. Trim excess fat from the chuck roast, dice onions, mince garlic, and chop carrots if using.

Heat a skillet over medium-high and sear the roast on all sides for about 4-5 minutes until browned. Transfer to the crockpot.

Layer chopped onions, garlic, celery, and carrots at the bottom of the crockpot. Pour in beef broth to slightly submerge the vegetables.

Sprinkle thyme, rosemary, salt, and pepper over the roast and vegetables. Cover and set the crockpot to low.

Cook on low for 8 hours or high for 4 hours until fork-tender, checking liquid levels during cooking.

Once cooked, let the roast rest for 10-15 minutes before slicing. Serve warm with veggies or creamy mash.