Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper.
In a large bowl, add the 2 pounds boneless, skinless chicken breasts cut into pieces. Season with 1 teaspoon salt, 1 teaspoon black pepper, 1 teaspoon paprika, 1 teaspoon garlic powder, and 1 teaspoon Italian seasoning. Drizzle the chicken with 1 tablespoon olive oil and toss until evenly coated.
Place the 2 medium cubed sweet potatoes and 12 ounces trimmed green beans directly onto the prepared baking sheet. Drizzle with the remaining 2 tablespoons olive oil and season with the remaining ½ teaspoon salt. Toss everything right on the pan.
Spread the vegetables out in a single layer and roast for 10 minutes to give the sweet potatoes a head start.
Remove the baking sheet from the oven and add the seasoned chicken pieces among the vegetables.
In a small bowl, whisk together 2 tablespoons honey, 1 tablespoon Dijon mustard, and 1 tablespoon lemon juice. Drizzle the honey mustard mixture over the chicken and vegetables.
Return the baking sheet to the oven and roast for another 20 to 25 minutes, stirring once halfway through, until the chicken is cooked through and the sweet potatoes are tender and caramelized around the edges.
Let everything rest for a few minutes before serving.