Heat the vegetable oil in a large, heavy-bottomed pot over medium heat.
Add the chopped onion and sauté until it becomes translucent, about 5 minutes.
Add the Cape Malay curry paste to the pot and cook for an additional 2-3 minutes, stirring constantly to prevent burning.
Add the chopped tomatoes and cook for another 5 minutes until they start to break down.
Add the diced chicken, lamb, or vegetables to the pot, stirring to coat them with the curry paste.
Pour in the coconut milk and bring the mixture to a simmer. Reduce the heat to low and cover the pot. Let it simmer for about 20-25 minutes, or until the meat is cooked through (if using meat) or the vegetables are tender.
Add the diced potatoes and carrots to the pot. Simmer for an additional 10-15 minutes until they are soft and cooked through.
Stir in the frozen peas and cook for another 5 minutes until they are heated through.
Season the Cape Malay curry with salt and pepper to taste.