Buy "The Food Lab", by J. Kenji Lopez-Alt (Kenji to you :)) https://www.amazon.com/Food-Lab-Cooking-Through-Science/dp/0393081087
Read it, follow his advice, try some recipes and do the experiments. If he tells you to stick your hand in a pot of cold water and then turn on the heat, do it.
Small Mason jars. Uniform, never going to be discontinued, and the lids are interchangeable, between 4 and 6 oz jars
Seconding Mercer. They make amazing knives. Their 8 inch chef's knife costs $40 and cuts as well as a $200 knife.
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The Noma Guide to Fermentation goes about as deep into the experimental depths of fermenting as anyone has gone, and the results are pretty mind-blowing.
Knives are very personal for some people, so I'm hesitant to recommend any higher end options. If you are on a budget, then one of these will probably be better than what he has today. One is smaller but forged, the other is stamped, but still well rated, even by Cook's Illustrated. If you're budget allows something higher than these, I'd just take him knife shopping.
https://www.amazon.com/Mercer-Culinary-Genesis-6-Piece-Tempered/dp/B000IBU9FW
https://www.amazon.com/Victorinox-Swiss-Classic-10-Piece-Cutlery/dp/B005LRYTA4
Get him a big ass knife. Lamson 8" Chinese Santoku Cleaver, Rosewood Handle https://www.amazon.com/dp/B0062ANEU0/ref=cm_sw_r_apan_glt_fabc_MCRBQY16N743ENRP69E9?_encoding=UTF8&psc=1
Kind of a joke but if.he his a chef he will always appreciate a knife or a kitchen tool.
I remember you from the non-stick question you previously asked. You've gotten plenty of good advice around stainless steel, so I'll focus on the non-stick aspect. While you could eventually wean off of it with a well-seasoned carbon steel or cast iron pan, for ease of us I'd continue with a relatively inexpensive non-stick skillet, such as https://www.amazon.com/dp/B000GWG0T2. Since you'll now have a stainless steel pan for things like high-temp cooking, you'll be able to avoid the behaviors that caused issues with your previous non-stick pans and will have something that will work well for eggs, pancakes and the like, while lasting for years. DO clean it after each use, or you'll still get that residue you had previously.
There’s different shapes for those small ones. You linked the wide mouth (and I really like those) but for 1/2 pint the regular mouth ones are a nice shape:
https://www.amazon.com/Canning-Regular-Wedding-Magnetic-SPANLA/dp/B07SH559GB/
If you’re mixing in pints though and stacking them the ones you linked are tits.
Most vacuum sealers intended for home use are going to be external vacuum sealers, so you're going to have difficulty with liquids no matter what you do (though by "difficult", I don't mean "impossible"). But my biggest problem with external vacuum sealers are the air gaps that are frequently left around bones in meats (and thus result in freezer burn). It could just be that the external vacuum sealer I have from years ago is outdated and too weak. I don't know.
That said, I have done an inordinate amount of research on this and I understand that these are your best two options if you aren't willing to go the chamber sealer route:
https://www.amazon.com/VS-12-Deluxe-Starter-Viewing-Compact/dp/B01KCK9W1K
https://www.amazon.com/FoodSaver-Machine-Automatic-Detection-Certified/dp/B00DI342IW
Note: those are not affiliate links. They are just the regular Amazon links. If you buy either of them, please send me a message after you test them and let me know how they work for you.