Wash the leaves and spin them until very dizzy but dry. Put them in a salad bowl. Preheat the grill to high.
To make the vinaigrette, beat the lemon juice with the sugar and Dijon mustard in a bowl. Peel and finely chop the garlic and throw it in with salt and a twist of black pepper. Beat in the oil with a fork until creamy, then put the vinaigrette to one side.
Tear the bread