Place the shrimp and eggs in a food processor with a metal blade. Pulse until the shrimp are coarsely chopped. Scrape the sides of the bowl and add the heavy cream, bread crumbs, salt, and pepper and pulse just to combine. Don't over-process the cream or you'll wind up with grainy textured cream or even butter. Remove the mixture to a bowl and add the chopped tarragon leaves, blending them in with a spatula.
Lay out one wonton skin on a board. Using a pastry bag or a teaspoon, place approximately one teaspoon of the filling in its center. Brush a second wonton skin with the egg-water mixture and lay over the filling, pressing lightly with your fingers to remove any trapped air and seal the edges of the wonton skins. Continue to make ravioli in this manner until all the filling has been used. The uncooked ravioli should be stored refrigerated in a container, sprinkled lightly with cornstarch. They will keep up to two days in the refrigerator, or for several weeks in the freezer. To freeze, lay the ravioli in a single layer on a wax-paper lined sheet pan and place in a freezer until frozen. They can then be removed and stored in freezer bags.
Heat the fish stock in a sauce pan and set aside. In another sauce pot heat the olive oil, add the chopped onions and cook until wilted. Add the crushed tomatoes and cook for 10 minutes before adding the fish stock and saffron. Continue to cook for 30 minutes until ready to serve.
To cook the ravioli, drop them into boiling salted water and continue cooking at a boil until they begin to float (about two to three minutes for fresh ravioli, 5 to 6 minutes for frozen ones). Drain and divide among soup bowls. Add 1/2 cup saffron broth to each bowl, garnish with a little diced tomato and some chopped fresh herbs such as tarragon or chives. Serve hot.