They are quite time-consuming to make from scratch, but fun! You will need a pasta-machine to roll out the dough to its thinnest, since you are sticking two layers together. The secret to keeping your ravioli in tact during cooking is to push all the air out of the ravioli when sealing it. Cook it in plenty of rapidly boiling, well-salted water. Dress with olive oil to stop the cooked ravioli from sticking to each other.