Most of it was from recipes created by people who have their own cooking blogs and the like. Sort of fan-fic for foodies, really.
There are loads of different takes and interpretations on the brief descriptions in the source material, and the Expanse novels make frequent mention of tank-grown fish or vat-grown meat, implying that it's much cheaper and more viable than farming animals, but still real meat as far as anyone cares. That's why this stuff appeals.
The Cyberpunk stuff used commercial brands of meat substitute, like Quorn, Facon and other textured veg proteins, with a few additions like pea protein, soy, tofu and some stuff I'd never heard of before like Asafoetida.
The burgers were okay... a bit like plant-based Whoppers, if you've ever had one of those. Not as good as a real decent burger, but not as horribly cardboard as the typical cheap catering supply burger from your local independent "Chik'n Grill" sort of dive... I'd choose this over McDonalds. It's more like the cheapest Iceland own brand beef burger, or a Rustlers microwave burger, but with much better taste.
There were a few others, but the one that stood out most was a Beef & Noodles one inspired by the early cutscene where you meet Jackie Wells at a street-side noodle bar. I had to go to the local Oriental food wholesaler to find all the less common bits, meat substitute and MSG, but honestly this one was as good as any other 'beef & black bean noodles' I've ever had. It reminded me of a vegetarian all-you-can-eat I used to frequent years ago, on Greek Street, Soho. I used to take all my meat-lover friends there, to amaze them (only after they'd stuffed themselves) by revealing the veggie aspect and seeing their faces when they couldn't tell the difference!!
The Expanse recipes were mostly Red Kibble, White Kibble and the famous Mariner Valley Lasagne.
The lasagne were the weirdest, as the authors usually opted for ingredients that were gluten-free dairy-free and just-about-everything-else-free, supposedly because you have no fresh food in space (aside from a few hydroponic plants, maybe) and everything else is too expensive unless you get processed powdered pretend versions of it.
Nonetheless, the results were still pretty good. I'm used to faffing about with my recipes to cater for guests who are veggie, vegan, Free from, or doing Paleo or Keto stuff, and many of the substitutions aren't that bad. Usually I'd place them at least on par, if not a couple levels above, high-end processed microwave meals.
I didn't go out and buy the sectioned oven dish that Alex uses in the episode... but I know you
can get them if you're that much of a fan!
The kibble variants are unusual, in that most of them remind me of fusion-style meals, like curried goat meatballs served with Italian style salads and pastas, or how Bobotie is like a Cape Malay version of cottage pie.
Most of it was great, actually, and the recipes you find online vary so widely that there's plenty of room for you to adapt things to suit your preferences.
Other recipes were essentially Oriental staples (mushrooms and noodles in black sauce) and meat was fairly common on stations or asteroid bases, so fake/processed ingredients were mostly stuff like cheese and wheat-based products.
Some of it does require a bit of messing about, doing the processing and blending of stuff to make other stuff, where you'd normally just get the real thing and start cooking with fresh ingredients, but as a fun Fan-Boy exercise in the kitchen and an exploration of what food in the future might be, it's a good laugh.