Extract the juice from the lemon and set aside. Add the water, wine, wheat berries, and the bay leaf to a pot. Peel the lemon and add the peels to the pot. Bring to a boil and then reduce the heat and cover. Simmer for about 2-3 hours, keeping an eye on the pan and adding more water if needed, until the wheat berries have softened and they start to split open a bit.
While the wheat berries are cooking, coat the chicken in a little extra virgin olive oil and some salt and pepper. Place the chicken onto a baking sheet and bake at 400°F until it is cooked through and not pink in the center. Let the chicken cool and then, using a fork, shred the chicken into bite-sized bits.
Once the wheat berries are done, drain off any excess water and discard the lemon peel and bay leaf. Add the chicken, dried rosemary, corn, and cranberries. Stir to combine, and add the fresh lemon juice. Add the toasted pistachios and sprinkle with the sliced green onions.
You can serve it immediately while still warm, enjoy at room temperature, or have it cold.