Hungarian Mushroom Soup

Chef's notes

Use Hungarian sweet paprika if you can find it — it has a deeper, more floral flavor than generic paprika and is central to the soup's character; smoked paprika can substitute but will shift the flavor profile noticeably. Whisk the flour into the milk thoroughly before adding it to the pot; any lumps in the slurry will persist in the finished soup, so take 30 seconds to get it smooth. The biggest mistake is boiling the soup after the sour cream goes in — keep heat on low and stir gently to avoid curdling; the target temperature is around 160 degrees F, well below a simmer. Prep the onions, mushrooms, and parsley before you start cooking; the stove steps move quickly and the soup benefits from not rushing the mushroom sauté, which concentrates flavor. The soup keeps refrigerated for up to 3 days; reheat gently over low heat, stirring frequently, as the sour cream can break if rushed over high heat.