Pumpkin substitutes for lasagne
(simple answer) I suggest finding a lasagna recipe without pumpkin in it.

Lasagna is a simple recipe and easily adaptable.

You can add and remove ingredients to your liking as long as you keep the basic structure of the lasagna (pasta/sauce layers).

Make certain that if you add ingredients to the lasagna, that they will be already cooked or can be baked in with the lasagna.