To start the gravy, dice the onions and slice the mushrooms. Heat a large stainless steel fry pan over medium-high heat. Note: The use of a stainless steel pan rather than a non-stick pan is important, as it helps to create the nice golden color and caramelized flavor of the onions and mushrooms.

Add the oil, followed by the onions and a pinch of salt. *Note: If desired, omit the oil and dry-sauté the onions with a bit of vegetable stock or water.

Sauté the onions until they are translucent and slightly browned, adjusting the heat as necessary. Next, add the mushrooms. Cook until their water evaporates and they start to brown nicely. Stir frequently to prevent any burning. Once the mushrooms and onions have cooked through and have nice color—which will greatly add to the flavor of the final gravy—deglaze with the vermouth* NOTE: you can replace the vermouth with an alcohol-free white wine, vegetable stock, or water.

Next, add the flour. **Note: Regular all-purpose flour can be used instead of gluten-free flour, if desired. Let cook for 30 seconds or so and then slowly add the water. Stir constantly. Add the first 2 cups of water and let come to a simmer before adding more water. You are looking for a nice gravy- or sauce-like consistency. Let it cook for a few minutes to cook out the starch. Add the tamari and apple cider vinegar. Taste for seasoning, adding salt and pepper as needed.

Additional Flavorings: If desired, add a teaspoon or so of Dijon mustard and/or horseradish or a little extra depth and flavor.