Hardware:
Very affordable on Banggood/AliExpress. For configuration examples see images and/or Fritzing (in the download).
Total cost: ~$/€ 40.=.

• Cheap 3L fries pan, max. 2000W ($/€ ~20,=)
• 28YBJ-48 DC 5V 4 Phase 5 Wire Stepper Motor With ULN2003 Driver Board
  (Buy a 4096 steps type, or change my degrees and stepper code)
• 220V, 2000W AC SCR (Volt and Watt depending on the used fries pan)
• Mini USB water pump, 5V, 100°C
• Micro switch
• 5V DC power, min. 700mA
• Waterproof DS18B20 Digital 1-wire temperature sensor
• 4.7K resistor
• 470uF elco
• 100nF ceramic
• 220V, 10A relay (.../WeMos/Solid state)
  (Volt and Amperes depending on the used fries pan)
• WeMos D1 mini
• PCB 7x9 cm
• Various mounting materials and wires (see images)

The PCB is mounted in the modified housing of the fries pan.