Vegan Salisbury Steak

Name: Vegan Salisbury Steak
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: American
Ingredients: 1 large onion, cut in half; 12-ounce packages of vegetarian ground beef substitute; 1/4 cup of breadcrumbs; 1 big egg (Optional); 1 tbsp garlic powder (divided); Black pepper and salt to taste; 1 tbsp olive oil (divided); 1-cup worth of fresh, sliced mushrooms; 1 3/4 cups of vegetable broth; 1/4 cup ketchup; 1/4 cup vegan Worcester sauce; 2 tsp cornstarch; 2 tbsp. Of vegetable stock