For the pressure cooker: Follow steps 1 and 2, transferring to pressure cooker and omitting coconut milk, sugar and fish sauce (if you brown the meat and vegetables in the pressure cooker pot rather than a non-stick pan, you will need to increase the oil slightly). Seal cooker. Place over high heat until steam escapes at a constant rate. Reduce heat to low. Cook for 15 minutes. Release steam following manufacturer's instructions. Stir in coconut milk, sugar and fish sauce. Simmer over medium-low heat for 5 minutes. Continue from step 3.