Preheat the oven to 220°C. Finely chop the garlic. Divide the cauliflower into small florets and mix well with the garlic and 2 tbsp. oil in an oven dish. Season with salt. Roast in the oven for 30 minutes, mixing thoroughly halfway through cooking. Whisk the lemon juice well with the remaining oil, salt and half the parsley.
Drain and roughly chop the capers. Add to the oven dish together with the pine nuts and roast for the last 5 minutes. When the carfol is ready, mix it with the dressing and leave to stand until needed.
Bring the vegetable soup to the boil, stir in the polenta, cook according to the packet instructions and leave to infuse. Then stir in the ricotta and some of the remaining parsley. Season the polenta with salt and pepper, serve with the cauliflower and garnish with the remaining parsley.