There's a big assumption that the probe is a K-type thermocouple, but if it is, then the MAX31855 is the chip for it. Not a "bad" assumption I suppose.
Thermocouples have a small variance in the voltage they output so you need something like the MAX31855 to amplify it. An Arduino has a precision of 1024 values between 0V and 5V, and, as an example, a K thermocouple only puts out ~3 millivolts at 160F.
As an aside, you can find lots of K-type thermocouples on eBay in a wide variety of styles.