Cut the mushrooms into halves. Peel and cut the shallots into halves (or onion into quarters). Wash and cut the root ends off the spring onions and coriander (about ⅓). Reserve the top ends of the spring onions and coriander. Peel the garlic cloves. Wash and slice the ginger.
Grill the mushrooms, chilies, garlic, shallots (or onion), spring onion and coriander root ends, and ginger until soft and just lightly charred.
When done, thinly slice the mushrooms, shallots (or onion), and spring onion and coriander root ends.
With a mortar and pestle, pound the chilies, garlic and ginger to a medium consistency. Add the sliced mushrooms, shallots (or onion), and spring onion and coriander root ends. Continue to gently pound and mix together. Use a spoon to help.
Add the fish sauce, padaek (optional), salt and sugar and gently mix well.
Taste and adjust to suit your palate. The flavour you're aiming for is a delicious balance of savoury, salty and spicy, with a hint of sweetness.
Thinly slice the reserved washed spring onion and coriander leaves and stir through with a spoon. As an option, garnish and serve with extra sliced spring onion and coriander leaves, and/or chargrilled chilies.
Enjoy with rice, pasta, bread, meats and/or vegetables.
Recipe by Ngeun Sysengthong at http://ngeun.net/jeow-het/