Add the onion and cook for 5 minutes until softened, then add the garlic and cook for a further minute until fragrant. Add the capsicum and cook for 5 minutes, stirring occasionally, until starting to soften. Add the pumpkin and cook for a further 8–10 minutes, as it takes longer to soften than the other vegetables. Stir occasionally to prevent catching on the base of the pot. Add the zucchini and eggplant, along with the remaining olive oil, and cook for another 5 minutes.