Start heating your oven to 220 C / 425 F / Gas Mark 7.
In a good-sized mixing bowl, beat the ricotta cheese with a spoon or electric mixer until it is smooth. Add the egg, bit a beat more to blend the egg in. Add the flour, and stir to make a consistent dough, but do not overmix.
Oil the bay leaves, and place them on a cookie sheet. Mould 4 flatbreads from the dough, and place each on top of a bay leaf. Cover, and bake until golden brown -- 35 to 40 minutes. Let cool on wire rack.
Optional sweetened version of libum that the Romans also made: just before the libum are done, zap the honey in the microwave to warm it. Spread the honey out over a dinner plate, and when the libum come out of the oven, place them to soak in the honey for about 30 minutes.
You need to cover these while they are in the oven. Use an upside-down ovenproof dish. Arrange the libum closely enough together so that they can be covered by what you are using as a cover, but not touching each other.