Melt the oil and butter in a large pan (or in a wok).
Add the onion and cook for 2-3 minutes.
Add rice, turmeric, cumin, chilli powder, garlic, chilli pepper, paprika, corn, olives and tomatoes and simmer over medium heat for 3 - 4 minutes.
Add the broth and bring to the boil, then reduce the heat, simmer the vegetables for 20 minutes while stirring.
Add cashew nuts and peas to the pan and simmer for another 5 minutes, stirring occasionally. Season to taste with salt, pepper and cayenne pepper and serve.
Tip: Do not pour in the broth all the way, but gradually add the rest and use a little more if necessary. The paella should no longer be watery, but neither should it be dry.
Tip: It tastes super aromatic if you add a few threads of saffron soaked in hot water instead of turmeric - a nutty aroma.