Preheat the oven to 350 degrees.  Coat a small baking dish with cooking spray.

Remove the mushroom stems and dice them finely.  Heat half the olive oil in a small skillet over medium heat, then add the onion and diced mushroom stems. Cook for 2-3 minutes or until tender and soft; add the minced garlic and cook, stirring constantly for 1 minute.  Remove from heat and let cool.

Combine the crab meat, mayonnaise, Parmesan cheese, most of the fresh parsley, sea salt, freshly cracked pepper, and a dash of lemon juice in a bowl.

Add the cooked mushroom and onion mixture, then gently stir until well combined.

Fill each mushroom with the crab filling until overflowing; repeat with the remaining mushrooms.

Place the mushrooms into the prepared baking pan.

Combine the panko crumbs with the remaining olive oil and the last bit of parsley, then mix until well combined.

Sprinkle the panko crumbs evenly on top of each mushroom.

Place into the oven and bake for 30 minutes or until the mushrooms are tender and the panko is golden brown.  Serve immediately.  Enjoy.