Heat the olive oil (2 tbsp / 30ml) in a large pot or Dutch oven over medium heat. Add the chopped yellow onion (1 large / about 150g / 5.3 oz) and sauté until softened and translucent, about 5-7 minutes.

Add the minced garlic (3 cloves) and grated ginger (1 tbsp) to the pot. Cook for another minute until fragrant, stirring constantly to prevent burning.

Stir in the ground cumin (1 tsp / 3g), ground coriander (1 tsp / 3g), turmeric powder (1/2 tsp / 1.5g), garam masala (1/2 tsp / 1.5g), and cayenne pepper (1/4 tsp / 0.5g) if using. Cook for 30 seconds, stirring constantly, until the spices are fragrant.

Add the cauliflower florets (500g / 1 lb) to the pot and stir to coat them with the spice mixture. Cook for about 2-3 minutes, stirring occasionally.

Pour in the diced tomatoes (400g / 14 oz) with their juices, the rinsed and drained chickpeas (400g / 14 oz), the coconut milk (400ml / 1 3/4 cups), and the vegetable broth (250ml / 1 cup). Stir everything together to combine.

Bring the curry to a simmer, then reduce the heat to low, cover the pot, and let it cook for 15-20 minutes, or until the cauliflower is tender when pierced with a fork. Stir occasionally to prevent sticking.

Season the curry with salt to taste. If the curry is too thick, you can add a splash more vegetable broth or water. If it's too thin, let it simmer uncovered for a few more minutes.

Serve the cauliflower chickpea curry hot over cooked rice or with naan bread. Garnish with fresh chopped cilantro (1/4 cup / 15g) before serving.