Heat oil in a large skillet over medium heat. Add onion; saute 5 minutes or until translucent and slightly browned. Stir in garlic and grated ginger root; stir constantly for 30 seconds. Add tomato; cook for 2 minutes. Stir in turmeric, cayenne, salt, paprika, and garam masala; stir constantly for 30 seconds. Add half and half, stock, and black-eyed peas.
Reduce heat and simmer 5 minutes, stirring occasionally. Stir in cilantro. Serve immediately with rice, chapati, or naan.