You may well have eaten it without knowing it. For example Heston Blumenthal states that ALL proteins in his restaurant are cooked this way.

I also think you're unusual in that most people imho would prefer not to have burnt and done bits and other bits rare or even raw - but would prefer consistency all the way through ie if they want rare - they want it all rare.

The only way you would be able to tell that a steak had been prepared sous vide and seared is that the steak would be "perfect" ie the extraordinary texture of the meat with toughness virtually removed and both the inside would be the same colour and degree of doneness from just under the surface to the center - something theoretically impossible to do by cooking any other way eg