Just experiment a bit, don't get anal about weighing ingredients, [unless it's a bake mix]
My favourite is Rattatuoille I can cook it but can't spell it.
Cut up veggies of choice, I like peppers, green, red and yellow[plus chillies if the kids are not having any] courggettes, mushrooms, tomatoes, celery, onions, leaks.
Stir fry some chopped garlic and add the onions, slowly add the veggies and stir fry for a while then add tins of tomatoes as required add salt pepper oregano [vegetable/chinese or italian OXO cubes add a nice bit of flavour]
Simmer this lot for atleast 20 mins and serve with pasta or riceor anything else you fancy.
For a special occaission just before serving add some single cream and stir in but don't let it curdle
The beauty of this is any left over can be refrigerated or frozen and used later, I usually cook a big Wok full and we have the rest later in the week even with common old pie & chips or sausage and mash, just add a dollop of rattattoulle.
Any stir fry stuff is easy just add a little of whatever you like.
Tinned soups are great for doubling as sauces and don't tend to be such a lottery in the making.