@Thatwentbadly I follow a plant diet mainly to reduce a very high cancer risk, DH and the kids eat anything. We usually have a couple of raw and cooked vegetables as our core, and I would have tofu/lentils/ and they would have a peace of meat/fish...
We do have some common meals, with a favourite being chickpeas salads, or polenta with a veggie base sauce, risotto, without the butter/cheese, a lot of soups.
Do you have a number for the low fibre (how much is low, a limit to stay under) because it is actually your DH making it tricky.
You can make vegan patties with chickpeas/mushrooms or falafel with chickpeas, socca flatbread with a ratatouille type of sauce.
There is of course hummus and all the dips in the world, you can have mexiacan fajitas with a selection of small bowls with shredded salad, tomatoes, beans, ...
Liquid smoke is a great ingredient to add to give the deep flavour one would get from soya sauce (or use a soys sauce substitute www.healthline.com/health/food-nutrition/soy-sauce-substitutes#TOC_TITLE_HDR_1 ) .
You should explore other countries' classics.
Dumplings, sushi, rice rolls, the last two are easy to make at home which each one have a specific filling .
You can make samosas and spanakopita and play around with the ingredients.
Do you have a Chinese or Asian supermarket? They have so many options you might want to explore.
If your family eats fish it helps, you can look up French recipes for mussels and clams, and Italian ones for fish meatballs, or even fish-based pasta sauces. Your DDs will get so much more calcium from anchovies than from supplements added to a oat milk.
Yes it is a vegan board, but within the "feed the world" section not the ethical living, so we don't bite .