Preheat the oven to 400 degrees
Remove the stems and using a spoon scoop our the gills of the mushroom caps.
Melt 2 1/2 tablespoons of the butter in a small saucepan over medium heat. Add the garlic and sauté until fragrant but not browned. Pour butter into a small bowl and brush both sides of the mushrooms with the garlic butter.
Place the mushrooms on a baking sheet and bake for 12 -14 minutes or until slightly soft. Using the same saucepan that you made the garlic butter, add the remaining 1/2 tablespoon butter over low heat until melted. Remove the pan from the heat and add the arugula. Toss until lightly coated in butter.
Poach the eggs in a medium saucepan. There are a few different methods to poach an egg. I use the vinegar method Here is a great guide to how to poach the perfect egg. Remove the mushrooms from the oven, place an even amount arugula in each mushrooms, top with poached egg, flaked salmon and sprinkle with grated goat cheese.
Salt and pepper to taste. Add a dash of cayenne pepper for a little kick and enjoy!