Heat oil in a small skillet over medium heat. Add chili powder, garam masala, turmeric, garlic and ginger; cook, stirring frequently, until fragrant, about 1 minute. Transfer to a medium bowl and stir in yogurt, 1/4 teaspoon salt and pepper. Transfer 1/4 cup to a small bowl and stir in lime juice and the remaining 1/4 teaspoon salt. Set aside.