Drizzle the olive oil over the bread and grill in a hot chargrill pan for 2-3 minutes on both sides, or until golden-brown and crisp all over. Turn off the heat but do not remove the bread from the pan.
Lay the sliced tomato over the bread and sprinkle over the crumbled Roquefort. Allow the cheese to melt slightly in the residual heat of the pan, then serve immediately.