Ingredients

• canola or other mild vegetable oil, for cooking
• 3 - 4 lb Only Alberta Beef beef blade, or other pot roast
• salt and pepper, to taste
• 1 onion, halved and thinly sliced
• 1 1/2 cups beef stock
• 1 1/2 cups barbecue sauce, plus extra to taste
• 2 tbsp brown sugar
• 2 tbsp balsamic vinegar
• 2 tbsp grainy mustard
• soft hamburger buns, for serving