In a large skillet over medium-high heat, heat oil. Add chili, garlic, and ginger and cook until fragrant, 1 minute. Add garam masala, turmeric, and cayenne and cook until toasted, 1 minute more.
Add potatoes, cauliflower, and vegetable broth and season with salt and pepper. Reduce heat and cook, covered, until potatoes and cauliflower are tender, 15 minutes. Garnish with cilantro to serve.