Temperature Control of Heating Element with Thermocouple

Goal of this work is to develop and then build system that would keep constant temperature in a given place or that of a given material (item), in this case it would be control system for a hot air soldering station heater with output up to 600W, with required adjustable temperature range of 150-500°C. Second goal of this work is to develop and then build this device using possibly simplest wiring and as small amount of components as possible