Heat oven to 375°F. In a large saucepan, bring 5 cups salted water to a boil. Add wheat berries, reduce heat to simmer, and cook until tender, about 60 minutes. If wheat berries look dry while cooking, add more water. Drain and transfer to a large bowl.

While wheat berries are cooking, slice squash in half vertically and remove seeds. Place squash halves cut-side down in a baking dish. Add a ¼ inch of water, cover loosely with foil, and bake 30 to 50 minutes until skin is pierced easily with a paring knife. Remove from oven and set aside to cool. Reduce heat to 350°F.

While squash is baking, separate chard leaves from the stems. Trim and dice stems and tear leaves into bite-size pieces.

In a large sauté pan or skillet, heat 1 tablespoon olive oil over medium heat. Add onions and cook 3 to 5 minutes, or until they start to soften. Add chard stems and cook, stirring, another 5 minutes or so. Add sausage and cook, stirring, until browned and cooked through. Drain excess fat from pan and add chard leaves. Cook, stirring, 3 to 5 minutes, or until leaves are fully wilted.

Transfer mixture to the bowl with wheat berries, add peppadews, and mix thoroughly. Add 4 ounces of Havarti and mix thoroughly. Season with salt and pepper.

When the squash halves are cool enough to handle, turn them cut-side up and sprinkle each cavity with olive oil and salt. Divide filling evenly between squash halves (about ½ cup each), cover loosely with foil, and bake 15 to 20 minutes more.

Remove baking dish from oven and remove foil carefully. Sprinkle squash halves with remaining cheese and bake, uncovered, another 15 to 20 minutes, until filling is hot and cheese melts. Serve hot or at room temperature.