In a large heavy bottomed pan, fry the bacon and onions together, set aside, save the grease.
Using the same large pan, on medium heat, add oil or grease of choice.
Mix water and arrowroot in a bowl, stir until it’s all incorporated.
Slowly add slurry to the grease, continually stir (it’s going to look gummy). Slowly add coconut milk and broth, continuously stirring. Stir until fully incorporated. As it simmers, slowly add the seasonings and nutritional yeast. Once this is all mixed together, let simmer for a few minutes, while stirring. Then, add the bacon and onions.
In a glass 9x13 dish, layer the sliced potatoes, drizzling the cheesy gravy in between each layer. But, save about 1 cup for adding halfway through cooking.
Bake at 350o for 30-40 min., adding the remaining gravy after about 20-25 min. of baking.