I think the last time I did chicken breasts I just sprinkled in garlic granules, some pepper and a sprig of rosemary and sous vide at 140 F for 3 hour, if you are busy and they go 4 hours no problem. Fresh garlic is not something you want to sous vide but granulated works fine. Steak is fantastic and I'd do that next. I hope you have a read up on the proper method for example once the chicken or whatever is done and you take it out of the bath if you are not going to eat immediately it should go directly into an ice bath. You don't want to give those anaerobic bacteria a perfect place to grow. Single layer the chicken breasts that way the heat will get to the interior of the meat quicker, you don't want to stack them on top of each other, lay them side by side. Don't be shocked by the paleness when they come out of the bag, slice a bit off and close your eyes and taste. You will very soon get over the appearance of the outside. Very important, save the bag juices, they are awesome.