Portobello and Havarti Burgers with Caramelized Onions

Ingredients:

• 2 tbsp olive oil divided
• 1 sweet yellow onion sliced thinly
• sea salt and fresh cracked pepper to taste
• 4 large portobello mushrooms stems removed and cleaned
• 4 slices of Havarti cheese

Mushroom Marinade:

• ¼ cup of balsamic vinegar
• 1 tbsp olive oil
• 1 tbsp fresh basil leaves chopped finely
• 1 clove of garlic minced
• sea salt and fresh cracked pepper to taste

Roasted Garlic Mayonnaise:

• 1 bulb of roasted garlic see recipe here
• 2 tbsp mayonnaise
• sea salt and fresh cracked pepper to taste

Serving:

• 4 hamburger buns toasted
• Tomato slices
• fresh basil leaves