Heat the oil in a wide pan over medium heat and fry the onion until golden. Season with salt, take the pan off the heat and stir in the smoked paprika so it blooms without burning.
Return to the heat, add the peppers and cook 3–4 minutes until they start to soften.
Add the eggplant with a pinch of salt, cover, and cook 5–7 minutes.
Add the zucchini, cover again, and cook 5 more minutes.
Add the tomatoes and stir everything together.
Taste and adjust salt and pepper. Simmer uncovered for 15–20 minutes, stirring occasionally, until thick and glossy.
Off the heat, stir in the fresh parsley.
