I see Marko beat me to it. I'm leaving it anyway. :-)
Freddy, if you can set the thermostat in your home, use a ruler, and tell time you can sous vide. I hope you like to read because here's a site (below) that fully explains the process.
Juicy pork? No problem. Rare tuna? No problem.
OK, here's the gist, but definitely go to the link and read. It also has charts so that you can figure out cooking times. It gives the math if you're into that. I just use the charts.
But the gist... Traditional high temp cooking over cooks the outside to quickly cook the center to the desired doneness. Use a thermometer to check the center and a given temp will be med rare every time the center reaches that temp. Just know the temp desired and the result will be perfect every time. At the same time the outside is cooking the meat is also killing off any bacteria that can make us sick. OK, that's high temp cooking.
Sous vide cooks at the desired temp the entire time. Want a perfect med rare steak? We like ours a bit more rare so I set our circulator to 129.8°F. The steak when finished will be a perfect med rare from edge to edge and in the center as well. But how do we kill the bacteria? Do you feel like procreating at 130°F? Well neither do the bacteria. Keep them there long enough and they'll die the same as we do. The key is to keep them there long enough. Start with frozen meat? There's a chart that tells us how long the bath will take to thaw the meat. Then it needs to be sanitized, then cooked. Just add up the times and that is the minimum time. SV is very forgiving, if you keep it in the bath longer it just gets tenderer but it can't over cook since (assuming our med rare) the bath never gets above 129.8 to overcook it. Find out how you like a steak, remember that temp and you'll nail it perfectly every time. The key for food safety is to always cook for at least the minimum times. I ALWAYS go over to make sure.
The steak can be eaten as it comes out of the poly bag, but DON'T! Spend a little more time, just minutes. Rinse off the steak and rub the cooked blood off of it. Save the bag juices for the dogs kibble, or use it in soup. Take the meat and dip it into a puddle of 50/50 solution of Dextrose and baking soda. The dextrose and protein when heated gives that fantastic grilled taste, and the baking soda promotes browning. I use a rack in a baking pan and place the wet dipped steaks on it, I use a butane torch since propane can give an eggy taste, but try propane and see. Then keeping the torch moving I brown the outside of them. Flip and do the other side. Do this where smoke won't bother. We have an outside venting hood over our range so I do it there. Serve them and get ready for compliments!
Could you brown in a fry pan? Sure! Or under a really high output broiler? Sure! But it's not going to be a normal broiler It must be a high output catalytic broiler to get hot enough to brown w/o overcooking the surface.
There's more to it but that's the gist.
Tips: Don't salt the meat before SVing it. It'll draw juices out and you don't want that. No EVOO added to the bag, it'll degrade from the heat and taste lousy. The same goes for fresh garlic but gran' garlic is OK. There's more, so read at the link. He also sells a book that goes into more depth. There are plenty of other sites online that are also worth time. But Baldwins site helped me the most with his charts and explanations. But that's me, I need to actually understand how things work. If that isn't you just skip over those parts at the link.
Freddy, it's not difficult even though it may seem as though it is at first. If you have questions get back to us and we'll help. Just don't give 5 minutes for a response. Don't do what my brother did either and serve unbrowned steaks to anyone. His wife told him to never serve her any of that garbage ever again. He knew better, I just don't understand him. But that's my brother. Following directions just isn't done. I showed him precisely how to do it.
http://douglasbaldwin.com/sous-vide.html
Freddy, I can't help you with the fish, I've never done fish in the SV bath. But it's no more difficult than a steak.
FWIW, I've served SV meat to non meat eaters and they absolutely loved it. I made a sampling and they had to try every one.
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FWIW, I bought another top round today at $2.99/# for a 5 pounder. I'll need to slice it thinner into 2 pieces to allow the heat to better penetrate it and when it's done in the bath I'll chill it rapidly and put it in the freezer, bag juices and all. When we want roast beef for sandwiches I'll thaw it at 129.8°F then do the dip and torch routine and thin slice it and the result will be every bit as good as the $15/lb roast beef from the deli. Not the first time of done this, I've added "Italian spice blend" to the bag as well as just gran' garlic and both were really good.