In a large, deep baking dish, spread half of the tomato sauce at the bottom. Add a layer of lasagna sheets.
Spread all the pumpkin mixture on top of the lasagna sheets. Add another layer of lasagna sheets.
Spread all the spinach ricotta mixture on top of the lasagna sheets. Add another layer of lasagna sheets.
Spread all the beetroot mixture on top of the lasagna sheets. Add another layer of lasagna sheets.
Spread half of the rest of the tomato sauce on top of the lasagna sheets. Add another layer of lasagna sheets.
Spread the rest of the tomato sauce on top and top with shredded vegan cheese.
Pour a little bit of hot water into the four corners of the baking dish. This will help keep the the lasagna moist.
Bake at 180 degrees celsius for 35-40 minutes.
Remove from heat and cut into slices. Enjoy!