Preheat the oven to 425°F.
Cut the sweet potato into wedge shapes and toss with a drizzle of olive oil, salt, pepper, and half of the dried herbs. Spread evenly on a baking sheet.
Roast the sweet potato wedges in the preheated oven for about 20-25 minutes, turning halfway through, until tender and slightly crispy on the edges.
While the sweet potatoes are roasting, season the chicken breast with salt, pepper, the remaining dried herbs, and a squeeze of lemon juice.
Heat a non-stick skillet over medium-high heat with a teaspoon of olive oil. Add the chicken breast and cook for about 5-6 minutes on each side until golden and cooked through.
In a small bowl, mix the nonfat Greek yogurt, lemon juice, minced garlic, and a pinch of salt and pepper to create the creamy sauce.
Steam or blanch the green beans until they are crisp-tender, about 3-4 minutes, then quickly sauté in the skillet for about 1-2 minutes to add a touch of crispiness.
Plate the chicken breast, drizzle the creamy lemon herb sauce over the top, add a serving of roasted sweet potato wedges, and a side of crispy green beans. Serve warm.