Add the onion juice and cook slowly for about 5 minutes until softened.
Stir in the flour and mix well until combined.
Gradually pour in the milk while stirring constantly to prevent lumps from forming.
Continue stirring until the sauce thickens.
Season the sauce with salt and pepper to taste.
Pour the sauce into a baking dish.
Carefully crack the eggs over the sauce, evenly distributing them.
Sprinkle bread crumbs quite thickly over the eggs.
Place small bits of butter over the top of the bread crumbs.
Bake in the preheated oven for 3-4 minutes or until the egg whites are set and the bread crumbs are golden brown.
Serve hot.
Notes / Tips / Wine Advice:
Wine advice:
Pair these rich and flavorful Lyonnaise baked eggs with a light and fruity red wine such as Beaujolais or a crisp white wine such as Chardonnay. The wine's acidity will complement the creaminess of the eggs and the richness of the sauce.