In a large bowl, combine chicken, Gruyere, bread crumbs, parsley, egg & garlic. Season with salt & pepper. Form into 4 patties & place in refrigerator until ready to grill.
Caramelized Onions
Heat oil in skillet until hot. Add onion & sprinkle with salt. Cook & stir about 15 minutes or until moisture is evaporated & onion is soft. Reduce heat; sprinkle with vinegar. Cook & stir until golden. Stir in brown sugar; cook & stir until caramel brown in color. Place in a dish; set aside.
Guacamole
In a bowl, coarsely mash avocados with lime juice & salt. Stir in garlic, onion & cilantro; blend well. Cover with plastic wrap & place in fridge until needed.
Portobello Fries
Preheat oven to 425 F. Place a wire rack on a large baking sheet lined with foil.
In a shallow dish, whisk together the flour, spices, salt & pepper. In another shallow dish, lightly beat eggs with 1 Tbsp water. In the third shallow dish, combine panko/butter mixture with the Parmesan cheese.
Gently toss mushroom slices in the flour mixture. Coat evenly & shake off any excess flour. Then, dip the floured fries into the eggs, drip off any excess eggs & then place them into the panko mixture. Gently press the panko mixture onto the mushrooms.
Place the fries onto the wire rack, leaving an 1/8-inch space between each. Bake for 15 minutes or until golden brown & crispy. If you wish, you could serve fries with marinara sauce, ketchup or a roasted garlic mayo.
Assembly
Once you have all the various components to this meal this far all that is left is to barbecue the chicken burgers over a medium heat for about 5-6 minutes per side or until cooked thru. Instead of baking the mushroom fries you can alternately grill them on the BBQ as well.
Slice & lightly grill Ciabatta buns. Top each bottom half with a chicken burger, a slice of cheese, some guacamole, caramelized onions & a tomato slice, ending with the other half of the bun. The big question is, how to get your mouth around it!
Recipe Notes
Whether you bake or grill, either way its all good!