This perfect party appetizer is stuffed with sweet onions sautéed in beef broth and fresh herbs. Topped with melted mozzarella cheese, you'll never look at stuffed mushrooms the same again!
Melt butter in a pan over medium heat. Add onions and caramelize for 15 minutes. Add in garlic cloves and continue to caramelize for an additional 3 to 5 minutes.
Stir in beef broth and cook for 2 more minutes.
Add onion mixture to a medium bowl and add in thyme and All-Bran cereal. Add about a tsp of filling to each mushroom and arrange on a baking sheet. Top with cheese and garnish with a little fresh thyme.