If you are using dried lentils and/or chickpeas, soak in water overnight. The next day, rinse thoroughly with cold water and boil each in a pot of water for about 60-90 minutes or until tender.
The oil I recomend for frying is vegetable oil. If you are health conscious, some healthier alternatives include avocado oil and peanut oil. They have a high smoke point (400 degrees and above) which make them great for frying at high temperatures.