This is the scheamtic made with Arduino UNO/NANO and a rotary encoder for control. In the code we use the readThermocouple() function to read the temperature and print the value on the i2c LCD screen. At the same time we create the PID loop using the feedback from the thermocouple and write a PWM signal to a mosfet that will control power. The rotary encoder will let you select the desired temperature and the P, I and D constants values.
Also check the part list here if you want to buy all the components.
