Preheat the oven to 375ºF. In a large bowl, combine sliced garlic, chicken, salt, red pepper, oregano, olives and half of the oil. Set aside on the counter while you prep the chard.
Stack the washed chard, cut, and discard the tough ribs at the bottom of the chard. Thinly slice the chard crosswise into ribbons.
Place the chard ribbons in your baking dish, and toss with the remaining half of the oil and whole garlic cloves.
Pour entire contents of the bowl with the marinated chicken thighs over the swiss chard.
Arrange in an even layer, making sure to tuck each chicken thigh into a ball with the longer, thinner pieces tucked under the flat, smooth side.
Bake for 25 minutes, or until the chicken thighs are cooked through with an internal temperature of 165ºF in the center of the largest chicken thigh, and the skin should be golden brown.
Top with raw peppadew peppers and serve.