INGREDIENTS
1 lb
lean ground beef (feel free to use fattier beef if you prefer)
1 1/2 tbsp
olive oil
1 tsp
salt
1 tsp
pepper
2 tbsp
unsalted butter
12 oz
sliced baby bella mushrooms
4 oz
fontina cheese, sliced
4 oz
sharp cheddar cheese, sliced
2 cups
fresh arugula
1/2
lemon, juiced
4
whole wheat buns, toasted
mustard aioli
1 1/2 tbsp
dijon mustard
1
large egg yolk
2 tsp
fresh lemon juice
1/2 cup
olive oil
2 tbsp
whole grain mustard
1 tbsp
horseradish
1 pinch
salt + pepper