3 lb (1.5 kg) rainbow chard
1 Tbsp olive oil
1 yellow onion, thinly sliced
1 clove garlic, minced
11⁄2 tsp minced fresh thyme
Salt and freshly ground pepper
2 cups (1 lb/500 g) ricotta cheese
1 cup (4 oz/125 g) shredded Gruyère cheese
1 Tbsp Dijon mustard
1 cup (2 oz/60 g) fresh bread crumbs
Preheat the oven to 375ºF (190°C). Butter
a 12-inch (30-cm) oval gratin dish.
Cut the chard leaves from the stems. Keeping
the leaves and stems separate, cut both into
1-inch (2.5-cm) pieces. In a large frying pan,
warm the oil over medium heat. Add the
chard stems and sauté for 2 minutes. Add the
onion, garlic, and thyme and sauté until
the onion softens, about 6 minutes. Add the
chard leaves and cook, stirring, until wilted,
about 4 minutes. Season with salt and pepper.
Transfer the chard leaves and stems
to a colander and drain well, pressing with
a spoon to remove excess liquid.
In a bowl, stir together the cheeses and
mustard. Add the chard and stir to mix well.
Spread the chard mixture in the prepared
dish and scatter the bread crumbs on top.
Bake until the bread crumbs are golden
and the gratin is heated through, about
20 minutes, then serve.