01 -
Heat the oven to 400°F and prepare a baking dish with enough capacity for the mixture and room below its rim.
02 -
Warm oil and butter in a broad skillet. Add onion and cook, stirring, until softened and deeply golden to preference; adjust heat instead of treating twenty minutes as a fixed endpoint.
03 -
Add wine and scrape up brown, unburned residue. Stir in thyme and broth, then bring to a controlled simmer.
04 -
Add gnocchi and cook according to the product’s requirements, stirring gently. Check tenderness and sauce consistency; reduce excess liquid carefully rather than baking a watery mixture blindly.
05 -
Taste before adjusting salt and pepper, then transfer to the prepared dish.
06 -
Cover with the measured Swiss or Gruyère and bake about 20–25 minutes, checking for a hot center and melted, lightly browned cheese. Shield the top if it colors too quickly.
07 -
Serve with toasted French bread alongside. Refrigerate remaining portions promptly in shallow containers.