Corvids like peanuts. If you get them still in their shells it cuts down on the pigeon mafia because they're not smart enough to open them. We also get jays when we put down monkey nuts.
We mostly feed fatballs which you can get quite cheaply in bulk from amazon (https://www.amazon.co.uk/gp/product/B0091SHOPG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 - this lot lasts for several months).
We've recently started getting a couple of rooks coming in - they actually pick up whole fat balls and fly off with them.... quite impressive to see, but I'm glad there's only a couple of them.