Preheat oven to 425℉. Line a baking sheet with parchment paper and set aside.

Add cubed potatoes and carrots to a bowl along with 1 tablespoon of olive oil, ½ teaspoon salt, ¼ teaspoon pepper, and ½ teaspoon dried thyme. Toss to coat. Pour onto one third of your prepared baking sheet and spread into an even layer.

Season turkey tenderloin on all sides with poultry seasoning and ½ teaspoon of salt. Place onto prepared baking sheet with potatoes, leaving space to add green beans in a later step.

In a bowl, add green beans, 1 tablespoon of olive oil, ¼ teaspoon salt, ¼ teaspoon of pepper, and minced garlic. Toss to coat and set aside (do not add to sheet pan yet).

Bake turkey, potatoes, and carrots for 20 minutes. Remove sheet pan from oven and add green beans. Return to oven and bake for an additional 15 minutes, or until turkey tenderloin is cooked through to 165 degrees Fahrenheit (I recommend using a meat thermometer for best accuracy).

Remove from oven. Allow turkey to rest for 5 minutes before slicing and serving.

Meanwhile, in a pan over medium heat, melt butter. Add minced onion and cook until softened and lightly browned around the edges. Add garlic and cook an additional 30 seconds.

Add flour and stir to coat onions and garlic. Cook for one minute.

Slowly add broth to pan, whisking continuously. Add poultry seasoning and whisk to incorporate. Cook for 3-4 minutes or until desired thickness is achieved, while whisking continuously.

Remove pan from heat. Season with salt to taste.