Do you offer veg and fruit? I started off giving things like well steamed carrots, broccoli (v messy!), sweet potato, courgette and so on. Very ripe avocado also went down well, along with quite ripe pear, nectarines, banana.
I also make lots of veg fritters by finely grating carrot, courgette or other "wet" veg. Mix with enough self raising flour to be able to shape into little patties and then fry. Protein wise, I started with things like hard boiled egg, grated cheese, tofu, quorn and so on (I'm a vegetarian).
Then after a few weeks I tried to move towards baby eating the same food as the adults. Now at 10 months he eats whatever we eat e.g. Shepherds pie, veg curry, enchiladas, homemade pizza, stir fry and so on.
Some people would say it's not entirely BLW, but I also give my DS things like yoghurt, porridge, semolina etc by loading a spoon and handing it to him. He eventually got the hang of getting it in his mouth, and now is beginning to try and load the spoon for himself.
At the beginning, it took my DS a good few weeks to learn how to chew and how to swallow effectively. It's best not to think about how much food they are eating, but concentrate on the skills they are learning. Once their hand coordination and mouth coordination get to a certain point they make a big leap in how much they actually consume. 27 weeks is very early on in the process - it sounds like you are doing fine!
HTH