French onion soup with homemade beef stock

Put the beef marrow bones in a roasting pan with half a cup each of roughly chopped onion, carrot and celery.

Roast at 450F for 35 to 40 minutes, basting throughout, until a good walnut brown.

Scoop the browned bones and vegetables into the pot but leave the fat, then boil water in the roasting pan and scrape up the fond.

Tie a large herb bouquet in cheesecloth with parsley sprigs, bay leaves, thyme, all-spice berries and peppercorns, not so tight that the herbs cannot breathe.

Fill the pot with at least six quarts of water, the chopped tomatoes, two each of onion, celery and carrot, and the herb bouquet.

Bring to a simmer, skim off the grey scum, add salt, and hold at a steady simmer with the lid on loosely for four to five hours, skimming scum and fat as needed.

Top up with boiling water if the liquid evaporates too far.

Cool, strain through a sieve, and refrigerate the stock.

Slice one and a half pounds of yellow onions through the root with a honed knife.

In a four quart saucepan melt the butter with the oil, add the onions, cover and cook over medium heat for 15 minutes.

Uncover, raise the heat to moderate, add salt and sugar and cook stirring very frequently for 40 minutes; without the stirring they scorch.

Slice the baguette a little under an inch thick and bake the croutes at 325F for 15 minutes.

Skim the set fat off the chilled stock.

Poach the egg in barely simmering water with a little vinegar for four minutes, then remove gently.

Oil both sides of the croutes and return them to the oven for another 15 minutes.

Rub the cut side of a sliced garlic clove over each croute.

He pushed them another 20 minutes past the 40 for a deeper dark brown.

Sprinkle the flour into the onions a little at a time and stir on the heat for three minutes.

Off the heat add the boiling stock and the vermouth, then salt and pepper.

Simmer partially covered for 30 to 40 minutes, skimming the skin that forms, and correct the seasoning.

Ladle the soup into bowls.

Top with three croutes and grate Parmesan and Swiss cheese over.

Add the cognac just before serving.

Variation: put a croute in the bottom of the bowl, set the poached egg on it, ladle the soup over, then more Swiss and Parmesan.

Drizzle a little olive oil on top and put under the broiler until the cheese browns.

Decorate with thyme.