Difficulty:[usr 1]
Prepare the Bechamel
Peel and slice the onions. Brown them gently in the butter
Cook the eggs for 8 minutes in salted boiling water, refresh them under cold water, then peel them, cut them into rings.
Add the golden onions to the Béchamel, gently mix the egg slices and the sauce, arrange everything in a gratin dish
Slide into the oven and broil for 5 minutes.
Serve immediately