Heat oil in a large skillet over medium-high heat. Add cauliflower and salt; cook, stirring occasionally, until lightly browned, about 2 minutes. Add water; cover and cook until the cauliflower is tender, 3 to 5 minutes. Add chickpeas and sauce; cook, stirring occasionally, until hot, 1 to 2 minutes. Remove from heat and stir in butter. Serve topped with cilantro, if desired.