Cut the halloumi into bite-sized cubes, dice the onion and tomatoes, and cut the cauliflower into small florets. To a pot over medium heat, add the olive oil and the halloumi cubes. Allow the halloumi pieces to brown evenly on one side, then flip and cook on the other side as well; this should take about 2 minutes on each side. Transfer the halloumi pieces to a plate.
To the same pot, add the onions, tomato paste, and cauliflower florets. Sauté for about 8 minutes until the cauliflower is slightly tender and the onions are soft and translucent. Continuously stir to ensure the cauliflower does not stick to the bottom of the pot.
Add the tomatoes, cumin, garam masala, red chili flakes, turmeric, curry powder, and garlic powder. Stir to coat all the vegetables in the spices evenly. Cover and cook until the tomatoes are soft and the mixture has slightly thickened.
Turn the heat to medium-low, then add the coconut milk and spinach. Stir to combine and allow the mixture to simmer gently uncovered until the spinach is wilted. Use a fork to confirm that the cauliflower is cooked through.
Add the halloumi back into the pot and stir one last time. Turn off the heat. Garnish with fresh chopped parsley. Store leftovers in an airtight container in the refrigerator and enjoy within 24 hours.