Preheat oven to 400 degrees F (200 degrees C) and butter a 12x8-inch baking dish. Set aside.
Cut the Russet Potato (7) in thin, round slices and layer with drizzles of Olive Oil (to taste) and a dusting of Salt and Pepper (to taste). Repeat till your reach around 1/2 inch from the top of the dish.
In a pan, heat 1 Tbsp Olive Oil (to taste) for a few seconds and add your White Onion (1). Cook on medium heat for around 5-7 minutes, or until golden.
Add your Garlic (2 clove) and Vegetable Base (1 tablespoon). Cook for another minute or two, stirring to avoid burning and to ensure everything is well coated with the flavor from the stock paste.
Add knobs of Butter (1/2 cup) and reduce heat to low. Once your butter has melted add in your All-Purpose Flour (4 tablespoon) and stir till all the onions are coated with flour. Increase heat to medium.
Slowly begin adding your Unsweetened Almond Milk (3 cup) and stir consistently as you do so. Once all your milk has been added a thicker sauce has formed you can go ahead and add your Lemon Juice (3 tablespoon) and Soy Sauce (1 tablespoon).
Stir again just before pouring over your potato layers. Top off with some Vegan Parmesan Cheese (1/3 cup) and cover with tin foil. Cook covered for 45 minutes and under covered for around 10 minutes. To add that golden brown effect you can broil just before serving!