In a large skillet, heat 1 tablespoon of oil over medium heat. Cook the onion in the oil for about 3 minutes, or until softened. Stir in the minced garlic and ginger and continue cooking until fragrant (about one more minute).
Add the spices by sprinkling the curry powder, turmeric, cumin, paprika, and red pepper flakes (optional) over the onion mixture. Cook for another 30 seconds.
Toss the cauliflower, bell pepper, and carrot into the pan with the spices, stirring well to coat them.
Add the coconut milk, diced tomatoes, and chickpeas to the pan and stir everything together. Bring mixture to a gentle simmer and cook for 15-20 minutes, or until the cauliflower is tender. (If the mixture thickens too much, add a bit of vegetable broth or water to thin it out.)
Meanwhile, if using tempeh, steam the cut pieces for about 5 minutes to reduce the bitterness. Add to the cauliflower mixture in the last few minutes of cooking. Stir with all the other ingredients and heat through.
Remove from heat and season with salt and pepper. Taste and adjust the seasonings to your preference. Serve warm over a bed of brown rice or quinoa. Sprinkle with chopped cilantro for garnish.