In a small saute pan over medium heat cook onion in olive oil until cooked about half way
Add mushrooms and garlic, saute until softened
Add worcestershire, balsamic and thyme, blend together
Add butter and toss. Move over to one side of pan, turn off heat and add arugula to empty side of pan to just barely wilt.
Grill burgers and add Beecher’s cheese after flipping
In a small bowl blend together garlic aioli ingredients and set aside
Assemble burgers: garlic aioli on each bun, burger,bacon, mushrooms, arugula