Another ginger-laced soup

Late home and needed to put a meal on the table fast for others dashing out to a concert. Butternut squash curry wasn't going to be on the table in 45 mins. On holiday in rented cottage. Kitchen equipped only with what I remembered to bring, which was not everything required for the recipes in mind. Inspiration struck on the bus home and luckily it worked:

Sweet potato and lentil soup

2 red onions
1 huge sweet potato (or two more average sized)
2 cloves of garlic
1 inch fresh ginger
1 red pepper
all the above finely chopped and fried in lots of olive oil. Onions first for 5 mins, then the rest for another 5-10. Add lentils, add water and a good dollop of harrisa paste. I used a new brand of paste (proper stuff from my local international supermarket) and it was a lot stronger than the supermarket stuff.
Cook 15 mins until veg is soft and lentils collapsing. Mush a bit with potato masher and serve. We added natural yoghurt and toasted pumpkin seeds. I think something green would have been nice with this. Maybe finely shredded fried cabbage?? Something green and crisp, not sure what else.