Stuffed Baked Onions with Liver and Béchamel

Preheat the oven to 180 °C. Clean the onions from their outer, dirty skins. Carefully cut off the tops of the onions (about one-quarter from the top), then place their 'caps' back on. Spread coarse sea salt into a baking tray, place the onions on it, and bake in the preheated oven for 45 minutes.

In a small saucepan, melt the butter over medium heat, add the flour, and whisk for half a minute. While continuously stirring, pour in the milk, reduce the heat to minimum, add a pinch of salt and mace. Cook over low heat, stirring constantly, for 10 minutes until it thickens. Then remove from heat and let it cool partially.

Reduce the oven temperature to 160 °C. Remove the onions from the baking tray and carefully scoop out their insides with a spoon. Leave the last layer of flesh and the skin. Finely chop half of the scooped-out onion flesh (use the other half for another dish).