Heat a large frying pan over medium to medium-high heat, add oil.

Add onions and basil and cook for two to three minutes, then add mushrooms. Let it cook over low heat for five to seven minutes till mushrooms lose their liquid.

Stir in butter. Then add white wine and cook till evaporated, mixing frequently. Taste and add salt or pepper if needed. Set aside.

Preheat oven to 350 degrees Fahrenheit.

Cut challah rolls in half and scoop out as much of the inside as you can.

Spread a thin layer of Pesto around the inside of the rolls, add shredded cheese, mushroom mixture, white cheese and some more shredded cheese on top.

Heat butter and basil cube in skillet over medium heat. Add challah rolls and cook two to three minutes on first side till dark golden brown, flip, then add some more butter and cook two minutes on the other side.

Place in a pan in the oven, and cook 20 minutes, flipping halfway through.