Preheat your oven to 400°F (200°C).
Start by tossing sliced sweet potato cubes in a small amount of olive oil, salt, and pepper, then spread them onto a baking sheet.
Place the sweet potatoes in the oven and roast for about 25-30 minutes or until they are fork-tender and slightly caramelized.
While the sweet potatoes are roasting, season the chicken breast with salt and pepper.
In a small bowl, combine the nonfat Greek yogurt, lemon juice, and chopped fresh herbs to create a creamy lemon herb sauce.
Heat a skillet over medium-high heat and lightly sear the chicken breast on each side for about 3-4 minutes until golden brown.
Reduce the heat to medium-low, cover the skillet, and cook the chicken until fully cooked through (internal temperature 165°F), about 6-8 minutes.
During the last 5 minutes of the chicken cooking, add the green beans to the skillet. Drizzle with the remaining teaspoon of olive oil and a pinch of salt, then sauté until they become crisp-tender.
Once cooked, plate the chicken, drizzle or dollop the creamy lemon herb sauce over it, and serve with a side of roasted sweet potatoes and crispy green beans.