So it seems that every time that I pan sear something, any oil I have in the beginning seems to be gone about half way through and it turns into me dry searing whatever I am cooking.  My guess is that I have the heat too high and the oil is evaporating or burning off.   Is there a simple way to know when the oil is hot enough to pan sear but not so hot that it burns off? 
If the oil is of too low temperature, it'll have a tendency to get soaked up by the food you're preparing or get evaporated together with the water that's leaking out, so that's where it's disappearing. (Some vegetables like eggplant, zucchini, ... tend to soak up oil like sponges regardless of the temperature.)  To test whether the oil is hot enough, I always use the empirical method:   slice off a sliver of whatever you're going to sear throw it in the pan   if bubbles start forming: oil is hot enough if not: throw away sliver, rinse and repeat    Works for anything  you're going to sear!  Having said that: Don't be shy on the oil: it doesn't just sear, it adds flavour too! 