That sounds like someone who knows what they're doing! Essentially that's sort of what I did. The issue with red lentils is that I find they break down too much (because I'm not diligent enough to stop cooking at the right time, probably) and I'm always looking for that bit of 'chew'. Hadn't thought of oats, though funnily enough I did use an oat milk towards the end as a thickener and to further bring it all together. But although the tofu worked (after quite a lot of baking) I found the end product a little 'granular' so added some tinned green lentils that simultaneously seem to be a bit hardier and bulk it whilst also blurring the lines a bit. It turned out quite well I thought, although the test will be how well it holds until tomorrow. Taste was good. Texture was good. My immediate family liked it. But although I'd probably get away with it in a lasagne, I'm not sure if I served it to meat eaters they'd love it.