Open-face steak sandwich with roasted sweet potatoes, onions and chimichurri

Wash the sweet potatoes under cold water, peel, and wash again.

Cut into quarter inch (about one centimeter) slices and put in a bowl.

Add the spice mix, the breadcrumb, a little olive oil, salt and pepper, and toss.

Spread a little olive oil on a parchment-lined tray, spread the potatoes on it and roast on the middle rack 15 to 20 minutes, checking at 15.

In the same bowl, coat the steak with a little oil and about half of the garlic; season with salt and pepper and toss again.

Heat a pan with a little bacon fat or oil and sear the meat, cooking it gently until medium rare.

Take the temperature: aim for 135, or stop around 120 for rare; it rises about 10 degrees more off the heat.

If the potatoes are not brown enough at 15 minutes, return them for three or four minutes more.

Take the meat out and let it rest. Discard the juice and fat from the pan.

Add fresh butter and all the onions, stir, and season with a little salt and pepper. Add the remaining garlic and mix.

Wash the parsley and cilantro and separate the leaves from the stems.

When the potatoes are soft, reserve them.

Add a little cold water to the onion pan to deglaze, then turn off the heat and let cool.

Mix the herbs with the mayonnaise and a little vinegar (or lemon juice) for the chimichurri sauce.

Brush the cut focaccia with olive oil, place on the tray and toast in the oven until slightly golden and crispy.

Wash the salad greens.

Slice the meat crosswise, against the grain.

Assemble: bread, a little sauce, salad, slices of beef, onions and more sauce; serve with the sweet potatoes.