Step 1

For the mushroom stock:Throw everything into a large pot and bring to a boil. Reduce heat to a simmer and cook gently for 1 hour. Strain through a fine mesh strainer. Discard solids. Cool and refrigerate for up to one week.

Step 2

For the mushroom congee:Heat a medium saucepan over medium-high heat until hot. Add oil followed by onions, cook for 2 minutes, stirring occasionally, until softened. Add sliced mushrooms and cook for an additional 2 minutes. Add garlic and ginger and cook for an additional minute. Add salt and stir to combine. Add rice and toast, stirring, for 1 minute. Add 12 cups of stock and bring the mixture to a boil.

Step 3

Reduce heat to a simmer and cook, stirring occasionally, until the rice breaks down to a porridge-like consistency, about 50 mins to 1 hour. If desired, add more stock to thin the congee to desired consistency. Season to taste with salt and ground white pepper. Serve with optional garnishes.