Not a jar, but I quite often fry chicken and onion/leeks, mushrooms and anything else in the cupboard, then stir in some philadelphia (as much or as little as you have/like) and add a little water to thin it out. Makes a really nice cheesy sauce.
I also make a large batch of tomato pasta sauce and freeze it in various snack pots/ice cube trays. Doesn't take long to defrost and only needs to be made once a month if you get a chance. I fry up a couple of onions, anything else in the cupboard/fridge (mushrooms, courgettes, beans, carrots, peppers etc) and a tin of tomatoes, add a little wine/balsamic vinegar, stock and herbs, seasoning and a teaspoon of sugar, then blitz it in a processor, cool and freeze.
With chicken and veg you could also do a stir-fry on noodles. Then the sauce would be finely chopped garlic, ginger and chillies (if you have them) fried in a little oile, then add veg and chicken, then add a little soy sauce. You could also add honey and vinegar and tomato puree (for a sweet and sour sauce) or some peanut butter (for a satay-style sauce).
Hope that helps!