Heat the olive oil in a large skillet over medium heat.
Add the sliced sausage and cook for 4–5 minutes, turning occasionally, until lightly browned. Remove the sausage and set aside.
Add the sliced onion to the same skillet and cook for 3–4 minutes until softened.
Add the minced garlic and sliced apples. Cook for another 3–4 minutes, stirring occasionally.
Pour in the chicken broth and add the Dijon mustard, maple syrup, thyme, black pepper, and salt.
Stir well, scraping any browned bits from the bottom of the skillet.
Return the browned sausage to the skillet and stir everything together.
Reduce the heat and simmer for 4–5 minutes, or until the apples are tender and the sauce has slightly thickened.
Taste and adjust the seasoning as needed.
Serve warm with your favorite side dish.