Some of our (rather boring) ideas...
Tuna pasta bake: tinned tuna, pasta, jar of pasta bake sauce, cheese for the top. We also cook some frozen beans to go with it (or salad items) to add some colour and vegetables!
Casserole: diced beef steak, root vegetables, tomato puree, beef stock cubes, Worcester sauce, bit of flour to thicken. Because we make this regularly, I have the ingredients in the cupboard all the time. Make loads (we use the slow cooker), freeze leftovers, makes a quick reheated meal with rice.
Curry: meat (we usually use chicken), jar of Indian sauce, vegetables such as peppers and potatoes. Another slow cooker favourite, again make loads and freeze the leftovers. Use old takeaway tubs to freeze and write contents on the lids with a marker pen.
BBC Good Food is a good recipe site and we've made some nice Jamie Oliver 30min meals (they take longer the first few times though).