Creamy with just a hint of mustard, this rustic gratin will warm you up on a crisp evening.
1 pound rainbow Swiss chard, with both stems and leaves intact
1 tablespoon whole-grain mustard
1¾ cup heavy cream
Sea salt and fresh ground pepper
Butter, for baking dish
1. Heat the oven to 350°. Cut the chard leaves from the stems. Chop the stems into short lengths, then cook briefly in boiling, lightly salted water until crisply tender. Remove the stems. Drop the leaves in the boiling water briefly, until they relax. Drain, let cool, and wring out the leaves. Spread the stems and leaves in a buttered shallow ovenproof dish.
2. Put the mustard in a bowl and stir in the cream and a grinding of salt and black pepper. Pour the seasoned cream over the stems and leaves, cover with grated Parmesan, and bake, 35 to 40 minutes, until the top is bubbly and golden brown.