I have marked up your food list to show my approach when I went through my own food cost reduction challenge
I make three types of food purchases...
Items that are frugal and form the bulk of my shopping. Buy as needed. Tend to be frugal, or fresh and lower priced per meal or serving. (Green). I eat different foods, so some of my staple items like squash, rutabaga, cabbage, cereal in bags, etc are not here.
Items to buy and stockpile when on super sale. Use a price book technique to learn the true loss leader sale prices (brown). These items you may even buy once a year in a large urban center if you know prices.
All other items are allowed, but are bought with a strict cash only weekly max budget. You set that amt. Pay by cc for the allowed items, but by cash for the extras.
A couple of thoughts...
Buy frozen- have you looked at fish, corn, peas, on, etc frozen? Some areas have fish only at $5/lb or less if frozen like pollack, cod, bass are cheap if not organic.
Peanut butter - are you feeding the birds with it? $10 per month should buy a couple big jars, at annual sale prices.
Make your own suet/fat and chicken stock. You certainly cook enough meats to do this. Pork butt renders to lard, chicken fat, beef suet, etc.
Homemade Stock is very easy and adds that extra for free to many dishes. Think about growing herbs like oregano and rosemary- many do well in rocky drier soils like Greece, so should give you nearly free meal boosts too.
Others mentioned pizza and bread for homemade. Really can be easy. Think about reducing the bird treats, like suet, even if you keep up with the seeds.
Very little processed foods, amazing there. Great job, this is usually the budget buster. Given that, the variety of breads is OK, just recognize that it is at a splurge level, in lieu of other treats.