Veganicity on a shoestring #3 - bean and veg casserole

Any raw foodists reading this will probably be throwing their hands up in despair at the turn my blog has been taking lately, but I am trying to eat healthily in the winter - with a very active life and no central heating at home - on a very tight budget, so the meals I've been posting fit that need pretty well. A lot of it is pretty consistent with 70s wholefood diets, except for the fact that I sometimes use tins! (oh and also white rice/pasta...)

This made one-and-a-half me-size helpings! (clue: I'm not small or currently off my food)

Ingredients
1 standard tin chickpeas
2 large carrots
Half a large onion
Half a standard tin of tomatoes (tomatoes are one vegetable that actually benefits healthwise from the cooking/tinning process, apparently it promotes some kind of useful nutrient)
3 teaspoons Bisto
1 tablespoon tomato puree
About two coffee mugs of water

Put the bisto and tomato puree in a saucepan and slowly stir the water in. Turn the heat on/up under it and keep stirring until the gravy thickens.

Slice the carrots, chop the onion, and put them in an ovenproof pottery dish (my blue glazed one is older than me, my mum had it first...) with the chickpeas and tomatoes. Stir so the ingredients are evenly mixed. Add the gravy so it covers everything.

Turn the oven up to 180/200 C (flexible depending on what else you want to put in there - I had it on higher at the start because I was making bread, since the oven happened to be on). Leave the casserole in for about an hour, until the carrots are cooked through. If you don't have either a dish with a lid or a handy piece of tinfoil, keep it on the bottom shelf and give it a stir at some point so the stuff at the top doesn't get burned!