Sauté Olive Oil, Butter, Onion, Garlic and Mushrooms for 3-5 minutes.
When onions are soft add ¼ cup Flour and cook about 2-3 minutes.
Add White Wine and place mushroom mixture in food processor and pulse to rough chop.
Add 1 cup Additional Flour, Egg and Mayonnaise and blend to form mushroom paste.
With an ice cream scoop or spoons form desired croquette size and refrigerate at least 30 minutes to set.
In separate container place 1 cup Flour (or more as needed) and Salt.
In separate container place Beaten Eggs, Water and Black Pepper.
In separate container place Breadcrumbs, Grated Cheese and Dried Parsley Flakes.
Roll chilled croquette in flour, then egg wash then breadcrumbs. Let rest 5 minutes in the refrigerator before cooking.
Bake in 375℉ oven on greased cookie sheet for 10-12 minutes or until golden. Alternatively, you can deep fry approximately 3-4 minutes until golden.