Pommes de terre en omelette (Potato omelette)

Although this is a simple recipe, it requires about an hour to complete, since each ingredient can only be cooked when the previous is done. It is a delicious brunch item.

A few strips of bacon (4oz/120gr) cut into lardons or paper clip-size pieces
1 Tbsp (½ oz/14gr) butter 
1 onion, chopped (6oz/170gr)
1 clove garlic, chopped
Splash of balsamic vinegar
1 Tbsp (½ oz/14gr) butter (yes, another one)
4 medium potatoes (about 2lbs), peeled, quartered and thinly sliced
5 eggs
½ tsp salt
Pepper, to taste

1. Heat a cast iron pan at a medium-high temperature. Cook the bacon until just starting to brown. With a slotted spoon, remove the meat and reserve in a medium sized bowl.
2. Lower the temperature to medium, add a Tbsp of butter, and slowly cook the onion until soft and translucent. This will take a while, maybe something like 20 minutes. For the last minute of cooking, add the garlic. Strain out and add to the bacon bowl for set aside.
3. Splash the balsamic vinegar in the hot oil and cook until the spitting and bubbling almost ceases - this is when most of the extra water will have been cooked away.
4. Add the potatoes with another Tbsp of butter and cook over medium-high heat, stirring occasionally, until it is soft and starts to brown.
5. Meanwhile, whisk the eggs, add the salt and pepper.
6. When the potatoes are cooked, use a slotted spoon to remove from the pan and pop into the bowl with the bacon and onion. Pour out all but 1 or 2 Tbsps. of bacon fat. 
7. Put the bacon, onion and potato back in the pan, stir to mix well, and then pour the egg on top, settling everything with the back of the spoon to make an even surface. 
8. Cover and cook at a low temperature until the egg sets, but the surface remains a little soft or runny or, conversely, cover and bake in the oven at 350°F until set.
9. Serve with cornbread muffins and a fresh salad or pickled onions and beets.