Mostly I make it up as I go along but something along the lines of
A can of beans in water (because I am too lazy to soak and cook beans) the ones that have no added salt or sugar. Drain and rinse them and drain well.
Then either whizz half and mash half or use a potato masher to mush them all up a bit (this only changes the texture, she might like it with them completely whizzed better, this makes a wetter mix so account for that in the later stages).
Add seasoning, for example a spoon of curry paste, or mustard, or tom puree and worcester sauce, or low salt seasoning powder, or pesto, or whatever herbs/spices you have in the cupboard, or even just a dollop of ketchup or bbq sauce!
Egg to bind it all together
whizzed breadcrumbs or couple of spoons of flour (optional but it's good to grains with pulses)
plus any additional veg you fancy (either whizzed so it cooks quickly in the burger or pre-coooked, could be left overs from the day before, mush up and add)
Once I've mixed it all together I either dollop tablespoons of it into a frying pan like a small pancake or form it into patty shapes (pretty random shapes here) and fry. If you want to change the consistency you can add extra bread or flour to thicken and just a bit of water to loosen. And if you don't want to stand over the frying pan as this takes longer then shove them in the oven.
Here's one were I actually took the time to write down what I did:
2" cube of mature cheese, grated (this added seasoning and some flavour but leave it out if you think it will put her off)
1 medium courgette de-seeded (to reduce the wetness of the mix)
1 can lentils, drained, rinsed drained (could be beans though)
1 spring onion chopped
3 mushrooms
2 tsp ketchup or bbq sauce
1 egg
0.5 pitta (can be any bread, I just had pitta left over)
low salt vegetable bullion
oven 200c
WHIZZ courgette, mushrooms, spring onion and bread
ADD to lentils, egg ketchup, seasoning and cheese
MIX well
GREASE mini muffin tray (or whatever you have)
BAKE 20 min.
I served some similar to this with flatbread, chili mayo (mayo with a dollop of thai sweet chilli added for me and DP) and mint mayo (mayo with a little mint jelly added for all of us) and a salad.
Mostly I put them in the freezer to use for DS's out and about snack/lunch.
Some little plastic tubs of dip would make it more appealing for a LO.
If you put the oven on for the beans you could put in an individual fritatta for her next day lunch box. Basically just an egg beaten in a ramekin, add a few bits like a sliced tomato, grated cheese if she will accept it mixed inside things, spring onion, or mushroom... and just let it cook and rise in the oven. It's like a quiche but without the pastry, stays firm enough to pick up as finger food.
Beans are SO great if you can get her to like them, really cheap (esp kidney beans although these are not DS's fav unfortunately). I used a can of mexican mix beans yesterday and it fed DS and I for 2 days, one day with tortilla wrap and one day with garlic bread.
I made ours with half can coconut milk, half aubergine, a courgette, an onion and a dollop of tom puree and threw in some spices, ground coriander, cumin, tumeric. Really cheap tasty easy meal and healthy too.