3 tablespoons butter
1 cup yellow onion (diced)
1/2 cup celery (finely diced, including leaves)
3 tablespoons unbleached all-purpose flour
2 teaspoons sweet Hungarian paprika
1/4 cup white wine
4 cups chicken stock
1 small head cauliflower (about 5 cups, cored and cut into small florets)
2 cups Gruyère cheese (8 ounces) (grated)
1/4 cup half & half (or whole milk)
  dash Kosher salt and freshly ground black pepper