The fresine is a type of long, wide spaghetti, with curled edges, used above all for the "timballo".
Clean the anchovies under running water, opening them, removing the heads, the central lisp and the tails; do the same for the sardines. Leave the anchovy fillets to dry over a kitchen towel. As to the sardines instead, pass them in the flour and fry in abundant hot oil. Drain and let dry on kitchen paper.
In the meantime boil the wild fennel in abundant water, then drain and mince. In a casserole heat three spoonfuls oil, then add the anchovies letting them melt, add the minced fennel, pour the tomato juice, season with salt and leave to simmer.
Boil the fresine in abundant salted water; drain them before they are completely cooked ("al dente"), then place the pasta in layers in a previously buttered pyrex dish (or baking-pan), alternating the pasta, the fried sardines and the red sauce; and so on until you finish the ingredients.
Bake in a pre-heated oven (180°centigrade) and cook au gratin for about 20 minutes, then serve.