What is your favorite cheap protein sources?

Hi everyone, <br><br>This thread is inspired by a post I read last night where someone mentioned that they use a lot of chicken breast for their meal prep. As a student I really wanted to try meal prepping to get healthier and because it is supposed to save money (win-win). I have been doing meal prep for pretty much 3 years now, and I eat A LOT of chicken. The thing is is that I really don’t want to eat that much chicken anymore, and I am definitely tired of it after so many years. <br><br>So I just want to know what you consider your favorite cheap protein sources? I personally think that chicken breasts aren’t cheap where I live (Europe), the only cheap alternative is chicken thighs (and sometimes even that). <br><br>I’ve tried mixing it up with Turkey and because they also have a breast part, I thought that that should work too, but I don’t like that as much as chicken breast (I know there’s different brands and qualities, just not really a fan) <br><br>Thank you for your time!<br><br>Edit: Wow, this kinda blew up! Thank you to all who replied, I never heard of some of these food items and I might try canned tuna. I’m not a huge fan of tuna so I might experiment with that!