Parry (separate) meat from fat and tendons. Wash the tomatoes.
Heat the olive oil in a pan and add the meat. Fry over medium heat, turning frequently. Do not fry for longer than 7-8 minutes (medium) - the meat should still be pink in the middle. Place on a plate and cover loosely with foil. Let cool, then cut diagonally into slices.
Wash the lettuce thoroughly, dry it and cut it into bite-sized pieces. Distribute on 4 plates. Now arrange tomatoes and lamb on top.
Put the olive oil, white wine vinegar, mustard, mint and sugar in a small screw-top jar and shake well.
Cut the cheese into 1 cm thick and 4 cm long pieces and pat dry with kitchen paper. Put the olive oil in a pan and fry the cheese over a medium heat for about 2 minutes until it is golden brown. Turn occasionally. Arrange the warm cheese on the salad. Shake the sauce again briefly, drizzle over the salad and serve immediately.