Set two sauté pans over medium heat and add enough olive oil to
coat the bottoms. When they’re hot, add the onion to one and the
leek to the other. Lower the heat slightly and allow both to cook.
The onion should cook low and slow for 45 minutes, or until deep
golden brown, like the onions in a French onion soup. The leeks
should cook just until translucent (about 10 minutes); then add the
wine. Bring to a boil, lower to a simmer, and keep cooking until all
the wine has evaporated and the leeks are “sec,” which is a fancy
way of saying “dry.” When both the onions and leeks are ready,
set them aside.
Preheat the oven to 450°F. Spoon a layer of the onions into a
gratin dish* and top with a layer of the leeks. Lay the sliced
chorizo on top and then finish by covering everything evenly with
the pieces of cheese. Bake until the cheese is melted and slightly
brown on top, 3 to 5 minutes.
While that’s baking, grill the bread on a grill or in a grill pan.
You can also use the broiler; you want the bread toasty and golden
brown. When it gets there, remove it from the heat and rub it all
over with the garlic clove. Start at the edge to help break the clove
up a little; then rub the clove across and drizzle with olive oil.
Carefully remove the gratin from the oven and serve right away
with the bread. It’s best when it’s bubbly and gooey and hot.
* To clean a leek, slice it in half vertically and hold it under
running water; this gets the sand out of each layer.* Though you could probably substitute more traditional French