Heat a medium-sized frying pan over medium heat and add a spoonful of dairy-free butter.
Add chopped mushrooms, and cook until mushrooms are tender and have released most of their moisture—about 6-8 minutes.
Add chopped fresh chives and cook a further 2 mins. Lower the heat.
In a blender, combine soaked cashews, water, garlic paste, nutritional yeast, salt and pepper and lemon juice. Blend on high until smooth and creamy. Taste and adjust seasoning if needed.
Pour the cashew cream into the mushroom and chives mixture. Stir to combine and heat gently until warmed through and slightly thickened, about 2–3 minutes. Add a splash of water if it gets too thick. Keep aside.