Slow Cooked Beef

Nope, but that did happen to my sister.... and she loves to cook. Messed with her smell and taste, and made things tough for her. & thanks, That reminds me I need to ask how shes doing with that.... last I knew it came back partially
Make sure she is aware of increasing evidence that vaccines can help long covid. I have a friend that had it for nine months. Got another jab at the beginning of the winter and was basically cured of his long covid within 24 hours. And, in case you are correctly suspicious of anecdotal evidence... studies suggest that covid,preventing and treating long covid.

But, yeah, it's still far from a sure thing...
Yes, that's the Maillard reaction. Thanks for explaining it to the laity. Sometimes I get too far ahead of myself.
I can’t even spell mallard.

But, yeah, the simple way to explain it is, that’s the crust.

I talked with a real-live chef one day. He said that a big part of cooking is layering flavors. So searing adds a layer, but it also leaves flavor in the pan and then sautéing something else in that pan brings some added depth of flavor.

It’s hard to do that in a crockpot unless you sear first, add the meat to the crockpot, then deglaze the searing pan and add that flavor into the crockpot too.

I don’t have an InstaPot but they do have a searing function so all that flavor can get cooked in when you shift it to the slow cooker mode.
What everybody else said. For tender, get a chuck roast and cook it low and slow. For flavor, what I do is sear in a bit of olive oil, then remove the beef, lower the heat a bit so the remaining bits don't burn, sautee some onions, then add some liquid like red wine and beef broth, then slow cook in an oven. You don't need crazy high temps to sear, or special oil. 350-400F is fine. One pot. I like to add quartered potatoes, carrot, and some onion halves. I think I put it in a 350 oven for about 4 hours.