Brasserie L'Ecole-style Mussels

Everyone loves the mussels at Brasserie L'Ecole and they're pretty easy to make. I didn't bribe any sous-chefs for the recipe or anything, I just figured it out. These are a perfect appetizer for 4, or meal for 2.

Ingredients:

3 slices good bacon
1 medium onion
1/2 large fennel bulb
1 bottle (not the honking huge kind, just a regular bottle) good medium-bodied beer. I used Phillips Blue Buck, but any ale will do. Brasserie uses La Maudite.
splash of apple cider vinegar
2 lbs mussels

Dice the bacon and slice the onion and fennel very thinly. In a large pot (big enough to fit all the mussels) put the bacon in while the pot is cold and start cooking it on med-low. When some of the fat has rendered out, add the onion and fennel. Cook on medium until onions and fennel are transparent then turn down the heat. Cook slowly, for a long time (around an hour), stirring frequently, until the mixture is thoroughly and uniformly browned and there are lots of stickies on the bottom of the pot.

Meanwhile, clean the mussels. The easiest way to do this is to empty them into a pot of clean fresh water, then pick them out one by one, brush off any grit or ickies and pull off their beards. If any are slightly open, squeeze them closed, release, and check that they then start to close on their own. If any do not respond, put them aside. Check the "aside" pile later for just slow ones that have subsequently closed - these can go in the pot, the others can go in the trash.

When you are ready to cook the mussels (ie, 5 minutes before you want to eat them), bring the heat up on the pot. Pour in the beer and let come to a boil and boil for about a minute. Add the splash of vinegar (this counteracts the bitterness in the beer). Then pour all the mussels in and slap a lid on. Steam for approximately 3 minutes. Once the mussels are opened, they're ready to eat. Discard any that have not opened. Divide the rest evenly between the bowls and then spoon the delicious liquid from the pot over top.

Serve with garlic toast or frites.