I made it twice in the last month and learned a few things. I think veal stock is traditional but I have no idea where you'd get veal bones unless you buy from a farm or a butcher.
Virtually all French Onion Soup recipes call for Thyme and Bay Leaf as the main herbs, done as a bouquet garni: Tied up, thrown in, then pulled out before serving.
Before you get started, I will say that the key is to slowly cook the onions. It took about 45 minutes. Here's how I did it:
- Melt some butter in a little olive oil on a lowish heat.
- Slice up some onions.
- I used about seven medium ones.
- Cover and fry gently until soft (about 10 minutes). Stir regularly - you don't want them to colour.
- I settled on three cloves because I love garlic. Add this to the pot.
- Turn up the heat a little, stir, allow the onions to slowly turn golden and caramelise. Another 10 minutes or so. Don't allow them to catch.
- This will help thicken the soup.
- I used about three cups. Add a little, stir, repeat.
- This helps to enrich the soup.
- Cover and simmer for about 20 minutes.
- Toast it. Then sprinkle some cheese on top and put it in the oven to melt.