Caramelize the onions in a frypan with ½ oil, sugar, thyme, salt and pepper then remove from pan. Add remaining 1/2 olive oil and heat it up. Add the mushrooms and cook for 1 minute, stirring often. Add salt and pepper to taste and then remove from pan.
For Best Results, gently massage Chimichurri Beef packages for 20 seconds prior to heating to separate meat into shreds. Empty contents of product into microwave safe dish and cover with paper towel. Microwave for 45 seconds stirring halfway. Let rest for 1 minute.
Slice baguette and brush the bread with aioli and fill with shredded beef, onions and mushrooms.