Makes 4 (side dish) servings.
1 1/2 lb baby spinach
1/2 small onion, finely chopped
2 tablespoons unsalted butter
2 tablespoons all-purpose flour
1 cup plus 2 tablespoons warm milk
2 tablespoons freshly grated parmesan
1/2 teaspoon salt
Pinch of freshly grated nutmeg
Cook spinach in 1 inch of boiling salted water in a large pot,
covered, stirring once or twice, until wilted, 1 to 2 minutes.
Drain in a colander and rinse under cold running water until cool.
Squeeze small handfuls of spinach to remove as much moisture as
possible, then coarsely chop.
Cook onion in butter in a small heavy saucepan over moderately low
heat, stirring, until softened, about 4 minutes. Whisk in flour
and cook, stirring, 2 minutes. Add warm milk and simmer, whisking,
3 to 4 minutes. Whisk in parmesan, salt, nutmeg, and pepper to
taste. Add spinach and cook, stirring, until heated through.