1 For the burgers: Soak the bread in lukewarm water.
2 Peel the shallot and garlic, chop finely and sweat in a pan with 1 tablespoon olive oil. Remove from heat and cool.
3 Mix the ground beef, egg, mustard, well-squeezed rolls and the shallot-garlic mixture and season with salt and pepper.
4 For the fries: Heat the oil in a saucepan to about 165°C (approximately 325°F). It is hot enough when air bubbles rise when a wooden spoon is immersed in the oil.
5 Peel the potatoes, cut into uniformly thick stips and pat dry.
6 Fry the potatoes in portions in the oil. Fry for about 5 minutes until they are soft but not yet brown and then remove from the oil.
7 Increase the oil temperature to about 190°C (approximately 400°F). Fry the potatoes in portions again for about 2 minutes until they are crisp and golden brown. Remove from the oil, drain well and sprinkle with salt.
8 Shape the meat mixture into 4 burgers and press slightly flat. Cook on a hot grill for about 4 minutes on each side.
9 For the salad: Meanwhile, rinse the arugula and spin dry.
10 Rinse the tomatoes, remove the stems and seeds and into very small cubes. Peel the onion and garlic and chop finely. Mix with the tomatoes, parsley, vinegar and remaining olive oil. Season with salt, pepper and a pinch of sugar.
11 Serve the burgers on plates with fries, arugula and tomato salad.