Pureé black-eyed peas in a food processor, or use a potato masher.
Add parsley, bell pepper, onion, ground pepper and thyme. Mix by hand until well combined.
Heat a large non-stick skillet over medium-high heat, and brush with a small amount of olive oil.
Form the pea mixture into 10 balls, each the size of a well-rounded teaspoon. Flatten the balls between your hands and set four or five in the skillet. When brown flip gently and brown other side. Repeat with remaining cakes.
Combine yogurt, tomato sauce and cayenne and serve with the warm cakes.