Add the vegetable oil, garlic, chilli paste and peppercorns to a hot wok. Stir-fry over a medium–high heat for 30 seconds, or until fragrant.
Add the squid, onion, capsicums and chilli and stir-fry for a further 1–2 minutes.
Add the oyster sauce, fish sauce, palm sugar, peanuts, coconut cream and a pinch of sea salt and stir-fry for a further 1½ minutes, or until heated through.
Garnish with extra chilli slices and serve.
Note: To make Cambodian chilli paste, soak 200g of seeded, large dried chillies in 500ml of warm water for 10 minutes. Drain, and then squeeze out the excess water. Pound the chillies to a paste in a mortar. Add to a hot wok with 1 tablespoon of vegetable oil and fry over a medium heat for 3 minutes, or until fragrant. Allow to cool, then refrigerate in an airtight container for up to 2 weeks.