They work fine.
Here is an example of a vegetarian lasgana where I use them.
The key is to make sure that there is plenty of well-seasoned liquid for them to absorb.
You don't need to parboil them.
cooking.stackexchange.com/users/1393/Michael Natkin
Lasagne typically need to cook in a hot oven for about 30 minutes.
The main problem, as outlined by others in this thread, is the tendency of pasta sheets to dry up during this prolonged exposure to high temperatures.
To avoid this, I usually precook the sheets in slightly-salted boiling water for one minute (I just want to soften them, not cook them); a few oil drops in the boiling water should help preventing the sheets to stick to each other.
Subsequently I drain the sheets and lay them on a clean cotton cloth to let the cooking water be absorbed while I attend the preparation of the sauces.
After lasagne are assembled in the pan, I cover it with aluminium foil and then put it in the oven to cook; after 20 minutes I remove the foil and let lasagne cook "naked" for the remaining 10 minutes.
Here are some pictures I took during the preparation of lasagne with crumbled sausages and mushrooms.
With this procedure, lasagne sheets retain most of the moisture, thus not needing an excessive amount of sauce to keep them hydrated.
I managed to obtain very good results even with Sainsbury's Value Lasagne Sheets (a brand of cheap "no precooking required" dry lasagne sheets commonly found in UK).
cooking.stackexchange.com/users/4770/Pino Pinto
I prefer the flavor of fresh lasagna sheets over dried but between the different sorts of dried sheets I've not found there to be a big difference in "no-precooking-required" ones.
I have however found that they vary a lot by brand.
The only thing I would say is that it can take a bit of trial and error to get a creamy texture with "no-precooking-required" ones as they soak up variable quantities of liquid depending on brand and how many layers you use so you can get a stodgy (but still delicious) finish.
Dropping the layer count by one and adding extra sauce has worked for me.
cooking.stackexchange.com/users/2391/vwiggins
Once again I will bring up America's Test Kitchen (AKA Cook's Illustrated).
They like the no-boil sheets, but they have experienced some of the same problems already brought up here.
To ameliorate those issues, they recommend soaking the sheets for 10 minutes in hot tap water before use.
I've done it, it works great.
cooking.stackexchange.com/users/20183/Jolenealaska
I've been cooking lasagne for the past 15 years and never had a problem with instant sheets.
I use meat sauce, cheese sauce and the sheets, I cook for about 30-35 minutes in a moderate oven and stick a knife through the layers to check if it's done.
Occasionally it will need an extra 5-10 minutes cooking time.
I love fresh pasta in every other instance
but I find that dried sheets are a lot better for holding the shape of lasagne!
cooking.stackexchange.com/users/39496/Anna
Do not boil the no-boil lasagna even for a minute.
I did this and ruined every noodle.
I can not unstuck them.
cooking.stackexchange.com/users/24368/Liz
I used dry sheets in cooking but found them hard in places where perhaps the sauce had not reached them
so decided next time to boil first as per the packet instructions for 10 mins.
Most of them stuck together so ended up with about 50% not useable - a right pain.
Give up - I will use fresh next time.
cooking.stackexchange.com/users/25633/Jayne
It is all about the sauce and the time.
If you are boiling your pasta sheets [or if you have fresh ones] the lasagna will be done within 30 min baking time.
However without boiling your sheets it would need rather an hour.
I am using a bit more sauce - making a ragù and using it generously.
I also use a bechamel-ricotta mixture [first make the bechamel sauce and when done stir in ricotta until smooth] - and use it also generously.
Mixing ricotta cheese and sauce together makes it very smooth [no usual graininess] - and you have more sauce - which your pasta sheet can soak up.
cooking.stackexchange.com/users/37588/Dominik MJ opinionated alchemi
I made mine without parboiling the pasta sheets and it was like concrete.
I suggest you parboil them for 2-5 mins so it can be soft but not cooked.
But I am no professional, it's just my opinion.
Hope it was good use.
cooking.stackexchange.com/users/41613/user41613
No cook lasagne noodles are better than those that require parboiling.
They shouldn't need to be soaked or cooked or parboiled.
They DO need to be completely covered in sauce.
To do this, I use fewer of the ricotta and Bechamel layers, and more of the tomato sauce layers.
I used to drain my tinned chopped tomatoes but now I add all the juice to my sauce and all the juice from the ground beef which I used to drain off.
If you test the lasagna when cooking by inserting a fork in several places you'll figure out how long it takes to bake it until the noodles are soft and
it's hot through.
The biggest issue I've had with the no cook noodles is that it's difficult to find disposable foil pans to fit the noodles without having to break them.
I make loads at a time (10 litres of tomato sauce, 5 1lb.
Tubs ricotta etc.)
There are apparently flat precooked lasagne noodles without the ruffled edge
but I've never seen them.
My family and friends love my lasagne.
As an added note, I don't bake the lasagne right away unless I'm serving it that night.
I usually freeze them without baking.
I put plastic film on top and then foil with a taped on note to be sure to remove the plastic then put the foil back on before putting it into the oven.
The frozen lasagne takes at least an hour to cook in a convection oven (9x11" pan).
I'd never go back to sticky wet lasagne noodles.
cooking.stackexchange.com/users/43386/smakcanada
I only ever use the packaged sheets.
I cook them in a frying pan, not a saucepan.
Start with hot tap water, no salt or oil added.
About 3/4 heat.
After 5 minutes, I use an egg lifter and slide between the sheets.
Stops them sticking together.
After 10 minutes, remove from stove and left one sheet out at a time and place on paper to towel to absorb excess water.
Works well every time.
cooking.stackexchange.com/users/73960/Jacky Vandenburg
I've always been a bit suspicious of "no-precooking-required" lasagne sheets.   What are the benefits and detriments of these sheets?   What would happen if you ignore the instruction and cook them a little in any case? I tend to do so - am I wasting my time?
How to deal with "no precooking required" lasagne sheets?
cooking.stackexchange.com
<pasta><lasagna>
cooking.stackexchange.com/questions/12089
cooking.stackexchange.com/users/373/Tea Drinker
This is usually not a problem at all, but you may find it difficult to ensure that all noodles are adequately covered and that they soak up the liquid evenly. No cook sheets are much easier as they don't require par boiling. Just make sure they are covered with enough liquid to cook.
The key is to make sure there is enough liquid covering them so they cook. You don't need to par-boil, which makes them much easier. 