leftover risotto soup

I had some leftover risotto kicking around in the freezer from this summer and an old bag of red lentils that never seemed to get used and were "bothering me". So I

• sweat a large onion in some olive oil, added a bit of diced carrot and celery, the washed lentils (about 1.5 cups), some thyme, a pinch of dried ginger and around 6 cups very light chicken stock (1 can + 5 cans of water)
• brought this to a boil and simmered until the lentils were tender
• stirred in the risotto to make a nicely thicked soup
• adjusted seasoning with salt and pepper

Lentils and rice is, of course, a classic combination, but using the leftover risotto gave me all sorts of bonus complexity at no added cost in time. "But PMC," you say, "isn't risotto making a branch of rocket science? Doesn't make this dish unfit for this forum?" Not so, as I think you'll see here.