In a Dutch oven, or another large pot, place the butter, olive oil and onions in, set heat to low
Continue to stir, being careful not to burn the onions, this is a low and slow recipe...patience is KEY! Once the butter is melted, you can turn the heat up a tad to a lower medium. This process takes about 1 and a half hours.
Once onions have reached caramelization, add all other ingredients and bring up to a simmer for 30 minutes
Remove bay leaf, Ladle into soup cups, leaving almost an inch from the top to place the toasted bread and the provolone cheese. Place under broiler to melt the cheese, until bubbly
