Preheat oven to 350F
Lightly grease springform pan (place base or foil under the pan to prevent liquid seeping out)
Pulse bread in food processor until it turns into crumbs
Line bottom of springform pan with breadcrumbs
Slice leeks in half and then cut into 1/2” thick semi-circles, wash thoroughly to remove dirt
Heat wok or large pan
Add 2 T olive oil
Add spinach and saute until it starts to wilt
Add leeks and salute, adding more olive oil if needed
Add minced garlic
When spinach and leeks are fully wilted remove from heat and pour into springform pan
In a separate bowl mix together milk, eggs, and herbs beating well
Pour egg mixture over the greens
Top with grated cheese
Top with mushrooms
Bake 1 hour or until set
Let cool 10 minutes before slicing