Heat 2 tablespoons of the olive oil in a heavy-bottomed skillet over medium heat. When hot, add the sliced scallions and cook gently for about 5 minutes, then add the garlic, yellow peppers, and zucchini. Add ½ teaspoon of sea salt, then partly cover the skillet with a lid. Reduce the heat to medium-low and cook until softened, checking about every 5 minutes and stirring with a wooden spoon, 18 to 20 minutes.
Remove the lid and add the passata. Cook over low heat until the passata has reduced by half, 8 to 10 minutes. Add the chickpeas and cook gently until married with the sauce, about 5 minutes.
Add the torn basil and remaining tablespoon of olive oil; taste for seasoning and serve.