- Boil ham hock in about a gallon of water for 1 hour, or until tender. Remove ham hock, shred, and chill. Reserve stock in refrigerator.
- Shuck corn, removing silk, then cut kernels from cob. In a skillet over medium heat, sauté kernels and onion in olive oil for 5 minutes. Let cool.
- To pot of cold stock, add peas, thyme, and bay leaves and bring stock to a simmer. Cook for 30 to 45 minutes, until peas are tender. Let cool.
- Remove herbs and strain peas, reserving stock. Combine peas with corn, shredded ham, and remaining ingredients except feta and sumac. Add ½ cup of stock and toss well. Season with salt and freshly ground black pepper, and top with feta, sumac, and a drizzle of olive oil. Serve chilled or at room temperature.