Ingredients

• 1 large onion, halved
• 1 ½ (12 ounce) packages meatless ground beef substitute (such as Impossible™ Foods)
• ¼ cup bread crumbs
• 1 large egg
• 1 tablespoon garlic powder, divided
• salt and ground black pepper to taste
• 1 tablespoon olive oil, divided
• 1 cup sliced fresh mushrooms
• 1 ¾ cups vegetable broth
• ¼ cup ketchup
• 1 tablespoon vegan Worcestershire sauce
• 2 tablespoons cornstarch
• 2 tablespoons vegetable broth