The words “that’s too much garlic” have never escaped my lips. Garlic should be added with wild abandon to recipes — one should double, if not triple the suggested amount — but, if that recipe is of the sous vide kind, you should definitely, without a doubt, cook the garlic before it goes into the bag.
Slow-cooked pork belly is pretty hard to improve upon. The uncured bacon steak is meaty and tender, with melty portions of delicious pork fat running through. It’s already indulgent, but you should make it even more so by giving it a sweet and crackly brûlée crust.
Sous vide cooking is great for a lot of things, but it’s very bad at browning. According to Harold McGee’s On Food and Cooking, most Maillard reactions occur around 120C or higher, while caramelisation doesn’t kick in until around 165C.
This is much higher than any recipe you would ever attempt to do sous vide, since water evaporates at 100C, and you can’t cook in an empty tub. (Plus, you would totally overcook your food — to get a nice, juicy medium-rare steak, you would cook it at 54C.)
Adding raw garlic to a bag of meat means you’ll end up with a lot of warm, still pretty raw garlic, which will add a harsh, acrid flavour to your food. It also — due to some sulfurous compounds — might turn green, which I have seen happen with my own eyes, and do not enjoy looking at.
Then there is the concern over botulism which, while very scary sounding, is actually quite small, as long as you keep the food out of the 3.3C-50C “danger zone” and practise good food safety. This is not to say it could not happen, but the risk is small.
The real danger lies in raw garlic ruining the flavour profile of an otherwise delicious, perfectly cooked meal — so sauté, roast, or otherwise cook the allium before chucking it in a bag. (Or you could simply use black garlic, which worked very well with this pork belly.)