Heat oil in a large skillet over medium heat. Add leek and 1/2 tsp. salt and cook until beginning to soften, about 3 minutes. Add garlic; stir for 1 minute. Add chickpeas and paprika and stir to coat. Add spinach and 2 Tbsp. water; cover skillet. Cook until spinach is wilted, about 2 minutes. Stir; season with salt.