For the pasta dough: Put the flour on a clean dry work surface. Make a hole (this is also called a well) in the center of the flour pile that is about 8 inches wide (bigger is definitely better here). Crack the eggs and yolk into the hole, and add the olive oil, salt and water.
Using a fork, beat the eggs together with the olive oil, water and salt, and then begin to incorporate the flour into the egg mixture. (Be careful not to break the sides of the well, or the egg mixture will run all over your work surface and you'll have a big mess! Also, don't worry about lumps.) When enough flour has been incorporated into the egg mixture that it won't run all over the place, begin to use your hands to get everything well combined. If the mixture is tight and dry, wet your hands and begin kneading with wet hands. When the mixture has really come together into a homogeneous mixture, THEN you can start kneading.
When kneading, it is VERY important to put your body weight into it--get on top of the dough to really stretch, not tear, it. Using the heels of your palms, roll the dough to create a smooooooth, supple dough. When done, the dough should look VERY smooth and feel almost velvety. Kneading will usually take from 8 to 10 minutes for an experienced kneader or 10 to 15 minutes for an inexperienced kneader. This is where the perfect, toothsome texture of your pasta is formed. Get in there and have fun!
When the pasta has been kneaded to the perfect consistency, wrap it in plastic and let rest for at least 1 hour.
For the shrimp and squid sauce: In a large pan, saute the fennel and onion in the oil until translucent, 2 to 3 minutes. Add the garlic, zucchini, tomato and some salt, and continue to cook, stirring occasionally, another few minutes. Stir in the red pepper. Add the wine, bring to a boil, and cook until reduced by half, about 3 minutes.
Add the chicken stock, bring to a boil, and simmer until slightly thickened. Add the shrimp and squid. Cook until just done, being careful not to overcook the shrimp and squid or else they'll be rubbery.
Take off the heat, set aside and keep warm.
For the arugula salad: Toss the arugula in the olive oil; season with salt.
To finish the pasta: Bring a pot of salted water to a boil. Roll out the pasta very thin with a pasta maker, following the manufacturer's instructions. Then use the machine to cut the pasta into tagliatelle.
Cook a quarter of the pasta in boiling water for 4 to 5 minutes (save the remainder for another use).
To serve: Divide the tagliatelle among 4 plates and divide the sauce over it, making sure each plate gets some pieces of shrimp and squid. Top with the arugula salad and some grated Parmesan, and garnish with fennel fronds.