Chop the onions and fry them with the squeezed garlic in a large saucepan with a little oil until brown (glassy is not enough). Peel the potatoes and cut into bite-sized pieces.
Put together with the drained and washed chickpeas in the pot and let heat briefly. Add tomatoes (whole and mashed), grate the ginger and add to the saucepan with all the spices (except chilli). Cover and simmer for 15 minutes. Season to taste with salt, pepper and chilli and season according to the degree of spiciness you want. Let simmer for another 15 minutes.