Cook rice according to package instructions. Meanwhile, in a medium pot, heat oil over medium-high. Add onion and cook, stirring occasionally, until golden brown, about 10 minutes. Add garlic, ginger, and curry powder and cook, stirring, until fragrant, 1 minute. Add chickpeas, tomatoes, and 2 cups water; bring to a boil over high. Reduce heat to medium, cover, and gently simmer 8 minutes. Add cauliflower and cook until cauliflower is warmed through and chickpeas are tender, 8 minutes. Stir in spinach and cilantro and season with salt. To serve, divide rice among four bowls and top with curry.