Preheat oven to 450F. Wash mushrooms, remove stems, spray the pan lightly with oil-based non-stick spray or mist with olive oil, and place mushrooms stem-side down on baking sheet or cast-iron pan
Bake mushrooms 5-6 minutes, just long enough to dry out some of the water.
While mushrooms cook, chop the olives, mushroom stems, and green onions, and crumble the Feta. Combine chopped ingredients with theBarney Bakery Almond Meal(or useBarney Bakery Almond Flourif that’s what you have), Greek Seasoning, and a drizzle of olive oil.
Stir to combine, then use a potato masher to mash the stuffing ingredients together. If the mixture seems dry, use a couple of drizzles of olive oil to make it stick together.
Fill inside of each mushroom cap with filling, pressing down so it stays in the mushrooms. (If you hold mushrooms over the bowl when you stuff them you can avoid making a mess in the pan.
Bake mushrooms for 8-12 minutes, until mushrooms are hot and slightly browned and cheese is partially melted.