Place all the ingredients into the bowl of a stand mixer fitted with the dough hook. Turn to medium speed, making sure that you stop occasionally to scrape all the flour down from the sides.
Allow the dough to knead for roughly 8 minutes or until the dough is very smooth and springs back lightly to the touch. Wrap the dough with cling film and leave on the counter to rest for 10 minutes.
Set up a pasta machine on its widest setting and fix it to the counter. Slice the dough in half and wrap one half back up in the cling film.
Liberally flour the surface and the rollers of the pasta machine. Using a rolling pin at first, roll the half of dough until it's just under 1cm thick. Flour the pasta and pass it through the machine on its widest setting a few times until you have a smooth, thin sheet of pasta.
Drop the setting on the pasta machine by one increment and run the pasta through, catching it on the other side with your hand, to make sure it doesn't fold and stick together. Drop the setting again and repeat the process until the pasta is thin enough to see your hand through (on my machine this is setting number 3)
By now you should have a very long, thin ribbon of pasta. Cut it in half down the width and lay both sides separately on a floured surface.
Making sure you leave sufficient space between each ravioli, pipe or spoon the filling onto on half of the pasta sheet. Brush off the excess flour between each blob of filling with a pastry brush. Dip the brush in a little water and gently wet the pasta around the filling.
Gently lay the second half of the pasta over the blobs of filling and carefully push out any air bubbles with the side of your palm until you have a bunch of neat little mounds of filling. Using a pasta wheel or a ravioli stamp, cut out the ravioli and reserve the offcuts of pasta. Repeat with the second half of pasta and remaining filling.
Allow the ravioli to sit, uncovered, on a plate for an hour or so. This helps them to dry out a little and makes the ravioli a little more robust when boiling.
Bring a large pan of salted water to the boil. Working in batches of around 3 or 4, add the ravioli to the pot and boil for around 3 minutes. Meanwhile heat a frying pan with a little olive oil, some crushed garlic and some sage leaves. Using a slotted spoon or spider, remove the ravioli from the pot and into the frying pan.
Fry the ravioli in the garlic/sage oil, being careful not to burn the sage, until the ravioli is lightly browned. Serve with sprinkle of flaky sea salt.