I have an ancient recipe book from when we first were vegetarian in the 70s and whilst the recipes’ serving suggestions are worthy of Neil from The Young Ones, the loaves and patties themselves are very good. Eggs are, IMO, necessary for binding, and if you can get your hands on a substance called Vecon (a sort of cross between Marmite and bouillon) that is excellent too.
I tend to make things up as I go along - grating up mushrooms, onions and whatever is in the bottom of the fridge and adding breadcrumbs, cheese and ground nuts before binding with eggs. I sometimes half fill the loaf tin then add a layer of tomatoes or sauce, then fill up the other half.
Equal quantities of cooked brown rice, grated cheddar and mixed ground nuts, mixed with fried onions and a bit of sage, formed into burgers and coated in egg and breadcrumbs are popular with adults and children alike, and don’t crumble.