In a large pot, heat the olive oil and onions over medium-high heat. Cook, stirring often, until soft.
Add cauliflower, passata, chickpeas, water and parsley. Season well with a generous pinch of salt and pepper.
Reduce heat to medium and cover with a lid. Let it cook, stirring occasionally, for 30-40 minutes.
Remove from heat, stir, and let rest for 10-15 minutes. It will thicken while resting. Sprinkle with Jensen 5 year old cheddar cheese and serve.