-
1
Heat 4 tablespoons of butter and the oil in a heavy-based saucepan, add the onions, garlic, thyme and bay leaf, cover with wet baking (parchment) paper and a lid and cook over a very low heat for 1 hour, until the onions have turned golden and are meltingly soft. During the cooking, stir the onions from time to time, to prevent them burning. Season to taste.
-
2
Add the wine, stock and sugar, then bring to the boil and simmer for 15 minutes.
-
3
Preheat the oven to 400u00b0F.
-
4
If the saucepan is ovenproof (if not, transfer to an earthenware soup tureen), place the bread slices on top, sprinkle with Gruyere and then drizzle the remaining butter, melted, over the cheese. Bake in a hot oven for 15 minutes or until bubbling and golden.
-
5
To make this in a slow cooker: Heat the butter and oil in a heavy-based saucepan, add the onions, garlic, thyme and bay leaf and cook over a medium heat for 10 to 12 minutes, until the onions have started to soften and colour. Transfer to your slow cooker, cover with wet baking (parchment) paper and a lid and cook on low for 5 to 6 hours. Turn the slow cooker to high and cook, uncovered, for 20 minutes to darken the onions, stirring from time to time. Add the wine, stock, sugar and seasoning, cover and cook for 40 minutes. Then continue with step 4 above.
