Easy and very silky creamy, great with mashed potato. Adapted from Epicurious.

2 lb. baby spinach
1 cup whole milk
1/2 cup heavy cream
1 small onion, finely chopped
2 tbsp. unsalted butter
1 tbsp. cup all-purpose flour
1/8 tsp. freshly grated nutmeg

Cook spinach in boiling salted water, stirring constantly, 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.

Heat milk and cream in a small saucepan over moderate heat, stirring, until warm.

Cook onion in butter in a 3-quart heavy saucepan over moderately low heat, stirring occasionally, until softened, about 4 minutes. Whisk in flour and cook roux, whisking, 3 minutes. Add warm milk mixture in a fast stream, whisking constantly to prevent lumps, and simmer, whisking, until thickened, 3 to 4 minutes.

Stir in nutmeg, spinach, and salt and pepper to taste and cook, stirring, until heated through.