Hi MegB, my DD 7.5mth is also self-feeding and it really is a challenge not to get into a rut, isn't it?
Any reason why you specify finger food? If DS enjoys self-feeding, no reason why you can't serve up portions of e.g. lasagne with various fillings (leftover veggies plus a can of tomatoes), a filled (cooled!) jacket potato, soups with dippers, spaghetti/pesto/mozzarella (wipe your walls after this one!), thick fruity 'porridge balls' (I just snip a few dried figs in before cooking). None of which take more than 10 minutes prep, apart from lasagne.
If toast is easy for you, though, stick with it, and use different flavours and textures on top - shop-bought nut butters, hummus, cream cheese stirred with spice/herbs.
Microwave-steamed veggies - baby sweetcorn, sprouts, broccoli dipped in a mild yogurt/sweet chilli sauce dip.
Buy flatbread, cover with tomatoes, pile on mushrooms/soft peppers/couple of olive slices, cover with cheese, whack in oven for 10, cool for 10. Hey presto, pizza!
Yes, all for a 6.5 month old! I've been keeping a food diary to appease the naysayers
And once you're happy with egg, so many more options Good luck.