You should, of course, ask.
Like K-Girl, I also enjoy real mail. But in this case, if you have the restaurant's email address, email would probably be preferable in that replying is so much quicker and easier.
In the particular case of gnocchi faits maison, I fear you might be disappointed as the difference that makes some gnocchi ethereal and others lumpen pastatariat is almost always touch and keeping the moisture level right. Potato gnocchi dough will always be wet. The trick is keeping it simultaneously as dry and as soft as possible, while kneading it as gently and minimally as possible -- but actually kneading and not flirting with it. That ain't easy, at least not until you get the hang of it.
If the gnocchi is too wet or not handled enough when making, it will fall apart when it's cooked. If too dry, it will be tough. If over handled (or too many eggs), it will be gummy.
Roll the gnocchi dough into ropes. Cut the gnocchi with a board knife. If you want grooves in your gnocchi to hold more sauce, put each gnocchi onto the back of a dinner fork and use just barely enough pressure to get grooves as you roll the gnocchi off the fork.
If your raw gnocchi aren't pillowy before they're cooked, they won't be pillowy when they are. Touch, touch, touch.
The ingredient list is very simple:
- Egg yolks;
- Salt, and perhaps
- Water (only if necessary, and very little).
Their ratios aren't very complicated either, although they can vary. Standard is three egg yolks, and 2 pounds of flour per pound of potato; salt to taste. Personally I like to use only as much flour as necessary to get a dough stiff enough to handle. Thus the amount of flour varies with the potatoes -- and potatoes can be quite variable depending on what kind of potato, how they're cooked, etc.
Generally, baking the potatoes is preferable to boiling them, and ricing is preferable to mashing. But -- and I hate to say it because it presents a true picture of how quirky and fussy cooking these kinds of things can be -- those differences aren't critical.