hmm... good point re: slow cooker. Hmm, can I not add them towards the end? Slow cooker is appealing as the kitchen is being gutted this week, so I can bung the contents in the slow cooker in another room of the way and still eat something vaguely nice in the evening!!
Nowt to go with, but I'm doing the week's shopping menu now and trying to use as much stuff up in the cupboards as possible ;)
I bung red lentils in at the end of a slow cooked lamb casserole (meat, carrots, onion, sweet potato usually). They thicken it up beautifully.
If you just want to do veggies and lentils, try putting some yellow or puy lentils in at the same time - they cook slower so add texture to the mush. And with just veggies I'd be tempted to add lots of Indianish spices