Few people know that bottled pastes have lots of uses beyond their purpose stated on the label.
For example, a green curry paste, bottled or home-made, can be used for braising to make a curry, its original purpose.
It can be added to a pan for stir- frying or rubbed into a chicken to roast. I have also used it to slather on a pizza base to make green curry pizza.
You can do the same with bottled nonya sambal chilli, hoisin, chilli bean, cincalok (fermented shrimp fry), gojuchang (Korean chilli paste) and other pastes, instead of leaving them neglected for months on the shelf.
Spice powders can be used in various ways, including being added to make spice combinations.
Someone wanted Cajun spice rub. I looked into my store and found paprika, black pepper, chilli pepper, oregano and thyme. That would do, with a pinch of salt to season. No need to buy the mix.
The same goes for curry.
Put together ground coriander, chilli, turmeric, fenugreek, cardamom and black pepper, with the first three dominating, and you have a fair approximation of curry powder.
Leftover curry powder can also be rubbed into meat before roasting or frying (tried curried chicken wings?) or it can be used to season stir-fries and flavour mayonnaise to make a curried salad dressing.
The point is that there are myriad uses for pastes and ground spices.