How to Make It
In a small skillet, heat the vegetable oil. Add the pine nuts and almonds and cook over moderately high heat, stirring, until lightly golden, about 2 minutes. Using a slotted spoon, transfer the nuts to a plate.
Add the walnuts to the skillet and cook, stirring, until toasted, about 3 minutes. Transfer the walnuts to a food processor and let cool completely. Add the pistachios and cashews and pulse until the nuts are finely chopped. Scrape the finely chopped nuts into a medium bowl.
Add the bell peppers and onion to the food processor and pulse until finely chopped. Transfer the pepper mixture to a fine-mesh sieve and press to extract as much liquid as possible. Add the mixture to the chopped nuts. Stir in the pine nuts, almonds, bread crumbs and olive oil. Season with salt and cayenne and serve.