Tomatoes that smell of tomato, grated on the coarse side of the box grater until only the skin is left in your hand. Salt them and leave them ten minutes.
Toast cut thick, rubbed with a cut garlic clove while still hot, then oil, then the tomato, then more salt than feels polite.
What goes wrong
Chopping instead of grating. You want pulp, not cubes, or it slides off the bread and onto your shirt.
