Thinly slice the leeks and add them to a large bowl. Cover with cold water and give them a good stir. Allow to sit for a few minutes for all the sand and grit to fall to the bottom.

Preheat a large heavy bottom skillet over medium high heat. Using your hands scoop the leeks from the water and add them to the dry hot skillet. Sautee until all moisture has evaporated.

Drizzle the leeks lightly with olive oil and season with a pinch of sea salt. Stir well and continue sautéing until the leeks have completely wilted and start to get some color.

Lightly oil a 10 inch round baking dish or line with parchment paper. Spread the cooked leeks in one layer on the bottom of the dish and set aside.

Rinse and dry the mushrooms on a lint free tea towel. (Depending on the variety used you might want to tear them into smaller pieces, half them or use whole). Add the mushrooms to the same skillet you cooked the leeks in and turn up the heat. Sautee long enough at relatively high heat so all the water released by the mushrooms evaporates (sometimes mushrooms release a lot of water sometime none at all). Stand by!

Push the mushrooms to the sides of the skillet and add a drizzle of olive oil in the center. Add the minced garlic and cook until the fragrant. (Do not burn the garlic.

Stir well then add the white wine and thyme. Continue cooking until the wine has evaporated. Season the mushrooms with a small pinch of salt, remove from heat and transfer to the casserole with the leeks. Spread in an even layer.

Add the cashew pieces, water, nutritional yeast, onion powder and salt to a very powerful blender such as a Vitamix. (If a less powerful blender is used, make sure to soak (or boil) the cashews in advance for 20 minutes in hot water before processing. Blend until creamy smooth.

Pour the cashew cream over the mushrooms and leeks and give it a little shake to evenly distribute. Cover with aluminum foil and transfer to the preheated oven. Bake the casserole for 45 to 50 minutes until the cream has set and thickened. Sprinkle with the crispy bread crumbs and serve hot.

Preheat a 10 inch skillet with 1.5 Tablespoon of olive oil over medium heat. Add the herbs and fry until crispy. Stir in the bread crumbs and toast moving them around until golden brown all over taking care not to burn them. Remove from heat and a dd a pinch of sea salt flakes.

To make the casserole compliant make sure to omit all oil or replace with water or veggie stock as needed.