Party sandwich fillings

Vegetarian sausage, Quorn fake ham with tomato, roasted peppers,banana and Cadbury’s Flake, and egg mayonnaise are all fine.

Both my little DGS enjoy houmous sandwiches ??

Peanut butter and strawberry jam (jelly in the USA) ?

Sorry, just noticed you asked for savoury and are already doing egg mayonnaise! Hummus on pitta bread, or even the Gregg’s vegan sausage roll!

Its been a long time since I did a childrens party but we went to one recently. Some of the sandwiches they had were cheese spread, cheese and cucumber, jam, Nutella and mashed banana.

I used to love banana sandwiches when I was a child.
Nice bread, best butter. You can't go wrong.
You could use avocado, sun dried tomato, feta and fancy fillings. M&S do some gorgeous veggie fillings for ideas esp if the adults are going to eat them.
For the children however, it may be less risky to stick to something you know they'll eat!
You're making me hungry.

I believe a lot of them like Halloumi these days.

I love tomato sandwiches - thinly sliced tomato with a sprinkle of salt and pepper

Cream cheese or Philadelphia with thinly sliced cucumber is also nice

Marmite is often popular with young kids

Are you allowed to have fish?
- tuna mayo
- prawn
- smoked salmon and cream cheese (use cheap trimmings)

Better not to risk peanut butter as there might be a child with an allergy. I second the idea of tuna - it's always been popular with my GSs. I wouldn't mind betting that if you put on avocado or smoked salmon for the adults, the children will scoff the lot! If you want a change from sandwiches, quorn sausages can easily be made into sausage rolls with a pack of ready-to-roll pastry.

I would imagine the allergy concern has been covered as the OP suggested Nutella ?

Philadelphia with finely chopped spring onions is delicious.

Hoummous and grated carrot go well on brown bread.

I don't think all cheese is vegetarian so you might need to check.

Well, after all that, dd found that the party venue has a pizza oven, so they're going to do pizzas instead.
So all I've made is a stack of chocolate fairy cakes with a Smartie on top.
Last night dh and I scoffed all the leftover Smarties (why is there no 'pig' emoji?) while watching Inspector Montalbano. And very nice they were too.

Cream cheese and cucumber, marmite and lettuce, cheese and chutney

Equal quantities of grated cheese and grated carrot, with a tiny amount of grated onion - and I mean tiny, you really don't need much! Mix together with mayonnaise for a really lovely sandwich filling.