Handful grated cheese (i like to use gruyere mixed with cheddar)
Add the butter to a heavy based pan over a medium heat then add the onions, a pinch of salt and a pinch of sugar, a few thyme leaves then place a lid on and cook until the onions collapse and become sweet and translucent,about 10 minutes then remove lid, increase heat a little and cook until rich & golden.
Add the flour & cook out for a minute or so then pour the broth over the onions & bring to a simmer skimming any fat from the surface.
Reduce by half or until deep flavour is achieved, season to taste.
Toast the bread in a frying pan until golden then top with cheese.
Ladle the onion soup into heatproof bowls, top with the cheese toasts & pop under a pre heated grill until the cheese is bubbling & golden.
