Mary, i use techniques rather than recipes when i cook so i don’t have any written details to give you. Just use the same basic technique you used to cook your pork tenderloins, only SV cook the pork loin about twice as long as the tenderloins. By the way, I consider an overnight brining to be essential with most contemporary pork, but it’s too late for that this time. Please try it sometime. It makes a significant difference.
Here’s what i do for all roasts with a few details for your gravy in particular. It starts with the meat. I’d whack up a large cooking onion and put half of it in the SV bag with the pork. Use any herbs you enjoy with pork. I like fresh rosemary, thyme, a little sage, and garlic with pork. Use more than you think you need. Put half of the herbs to cook with the pork.
When the pork is just about done lightly brown half of the remaining onions in your fat of choice. Some bacon fat brings a smoky-piggy flavour to your meal and you’ve already paid for it. Make a tan roux in the pan with the fat and onions. You’ll need about a tablespoon of flour for each cup of finished sauce. You will probably have to loosen the roux with more fat. Do it. You want your roux to be very slightly runny. I figure on each cup of sauce serving about two guests generously. That’s two ounces per portion for service with the rest offered at the table. If you’re not serving gravy at the table you will get three servings per cup. (Get yourself a 2 oz. ladle.)
As usual you decant the cooked pork, straining and reserving the juices, onion and herbs separately. Use your usual sear technique, or not. I always do. Stir in the remaining raw onions to the roux. Now whisk the pork juices into the roux, bring to a boil while stirring for a minute and simmer. You know all this. You will likely have to add some stock or beer to get the right consistency. Or add some of the wine you plan to serve. If all else fails, water will do, but just. Stir in the SV cooked onion and herbs and adjust seasoning with sea salt and freshly ground black pepper. Please taste as you go. Before service stir in the reserved fresh herbs, starting with about half, and taste, so you get that just-right flavour and aroma.
Mary, you always have 2 spoons on your cooktop, don’t you? One spoon is to take a sample and deposit it on your tasting spoon. If you are right-handed, your tasting spoon is always on your right. Seeing cooks take a spoon out of their mouth and putting it back in food drives me crazy. Fingers are even worse. Shows no respect.
You probably don’t want to know why there’s three additions of onion, but i’ll tell you anyway. The result is a subtle blend of onion textures and flavours that adds complexity and makes your gravy uniquely delicious. There’s other little tricks like adding a bit of anchovy or soy sauce, but i’ll let you discover them on your own.
Enjoy your dinner.