First thing first: they are called lasagnE non lasagnA.
Second: you can make everything homemade but that might take you 24/48 hours (I usually need 30 minutes max).
Lets'start:
Prepare the soya mince as explained in this post , once ready add to the pot 2 can of Lidl tomato sauce and I can of white sauce (I found that the St. Bernard from Dunnes Stores is the closest to besciamella)
You should get a nice reddish tick sauce like this
Now for the lasagne: I suggest to boil them , or as I do, sink them in hot water for 5 minutes until they get soft. Whatever you choose be careful: they stick together!! Add I tablespoon of oil to the hot water to avoid it
Add a thin layer of sauce to the bottom of the oven tin to avoid the lasagne stickin while cooking
Add the first layer of lasagne
Cover it with a layer of sauce, parmesan and grated cheese (Mozzarella or Cheddar)
Keep repeating the same order of ingredients until you finish your lasagne and you end it up with a layer of sauce and cheese
Bake it for about 45 minutes at 180 ....
...Buon appetito!!