Ring-My-Bella Mushroom Sandwich | Hungry Girl

Ingredients

• 1 large portabella mushroom cap (stem removed)
• 1 thick slice red onion (rings intact)
• 1 tsp. olive oil
• 1/8 tsp. salt
• 2 dashes ground thyme
• 1 stick light string cheese
• 1 light English muffin
• 1 tsp. light whipped butter or light buttery spread, room temperature
• 2 dashes garlic powder
• 1 tbsp. light mayonnaise
• Dash cayenne pepper
• 1/2 cup shredded lettuce
• 1 large slice tomato