2-3 tbsp olive oil3.5 oz shiitake mushrooms, sliced (1.5 cups sliced)1 small yellow onion, diced1 leek, halved and sliced into half-moons (light green & white parts only)1 tbsp soy sauce3.5 cups water or broth1/4 cup heavy cream1 15oz can cannellini beans, drained and rinsed1.5 tsp kosher salt1.5 tsp garlic powder1/4 tsp ginger powdercornstarch slurry (1 tsp cornstarch + 1.5 tbsp water)
Heat 2-3 tbsp olive oil in a large pot over medium heat. Add sliced and washed leeks and stir until soft. Add 1 diced yellow onion and sweat until softened, about 1-2 minutes. Add 1.5 cups sliced mushrooms and 1 tbsp soy sauce. Continue to saute and stir until the mushrooms are lightly browned and softened. Once mushrooms are cooked, add 3.5 cups water/stock and stir. Bring to a boil, then lower to a gentle simmer. Stir in 1/4 cup of heavy cream and season with salt and pepper. Gently stir in the drained and rinsed cannellini beans.
In a small bowl, whisk together 1 tsp cornstarch with 1.5 tbsp water to create a slurry. Ensure there are no lumps remaining. Pour into the soup and bring to a gentle boil to thicken slightly. Add 1.5 tsp garlic powder and 1/4 tsp ginger powder and stir. Taste and adjust as needed.
Enjoy while hot, or store in individual containers in the fridge.