Using Soy Meat in Lasagna
Assuming TVP is what you used... it is essentially a byproduct of the production of tofu, and as such is largely tasteless on its own. Generally, to use it you first rehydrate it with a 1:1-1.5 ratio of TVP to liquid. The liquid can be pretty much anything, from water, to broth, mustard, ketchup, liquid smoke, etc. Very similar to tofu, it will absorb the taste of whatever you prepare it with. When cooking it for vegans I usually use vegetable broth, water, vegan worcestershire sauce, a dash of liquid smoke and Bragg's Liquid Aminos (the liquid aminos and worcesershire sauce add some of the savory that you REALLY need to simulate beef). A small amount of sherry works well here too. 

Stir the liquids, and add them to the TVP and allow to rehydrate for about 10 minutes. Check about 5 minutes in and ensure you have enough liquid. It's usually better to have too much than too little as you can pour off the excess. You'll have to play around with what flavors you use in the liquid - as mentioned, TVP is more or less a blank palette. This is actually both a boon and a burden compared to store bought "meat crumbles" which are already seasoned.

After rehydrating, it is ready to eat. You just need to warm it. So in the future, you can sweat your onions while it is rehydrating, add the sauce, and add the TVP last (just to bring it to heat). You'll have to play around with flavors that work best here. Sorry I can't be more specific, I usually don't use TVP for lasagne.

HTH