You are in a really mild climate... Make use of it and grow herbs, soft fruit, tomatoes, salad greens.
All really easy to grow but hard to transport so are expensive in the shops.
Create a tasty turnip cupboard of spices - make up your favourite flavours. For us it is bay spice, fajita, abodo, berebare, quate espice, chicken rub, five spice to give us US tasty, Tex mex, Ethiopian, french creamy, BBQ rub, Chinese base flavours. You can then add them to whatever fresh ingredients are about at the time. A pack of chicken legs can become a curry (of whatever flavour), stir-fry,kofta,BBQ,roast,kababs, pasta sauce, meatballs, dumdum, ramen soup, a soup of some other type, Cesar salad.... The choice is endless.
The general rule is the more work someone else does the more expensive it is for you. If you can easily take their work from your costs by doing it yourself then it is cheaper.
Grow your own -cheaoer because you aren't paying for someone to bring it to you in pristine condition
Cooking from basics... You aren't paying for someone to chop your onions or stir your sauce.
Look at what you like and see if you can do it cheaper. Practice helps too - when we started reducing food bills I would never have attempted flat breads (naan, tortilla, pita et al), Chinese dumplings, fresh pasta but now see that as an everyday thing.
Flour is the cheapest bulking ingredient... Bread, pasta, dumplings, cobblers, seiten etc are cheaper than potatoes or rice.