Preheat oven to 400°. Toss breadcrumbs, oil, and
lemon zest on a rimmed baking sheet; season with
salt. Toast, tossing once, until golden brown, 8–
Meanwhile, cook chard leaves in a large pot of
boiling salted water until tender, about 1 minute.
Drain; transfer to a bowl of ice water to cool.
Drain and squeeze well in a clean kitchen towel to
remove excess moisture.
Heat butter in a large saucepan over medium heat.
Add shallots and chard ribs and stems, season with
salt and pepper, and cook, stirring often, until
tender, 5–8 minutes. Add cream; bring to a boil,
reduce heat, and simmer, stirring often, until
thickened, about 4 minutes. Add chard leaves and
cook, stirring, until warmed through and coated
with cream sauce; season with salt and pepper.
Top Swiss chard with breadcrumbs just before