1. Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Season the chicken tenderloins with salt and black pepper. Place them in the skillet and cook for about 3-4 minutes on each side, until golden and cooked through. Remove and set aside.
2. In the same skillet, reduce heat to medium and add the remaining olive oil. Add asparagus pieces, sautéing for 3 minutes until they start to soften.
3. Toss the sliced mushrooms with a pinch of salt and add them to the skillet. Cook until mushrooms are tender and golden. Push the vegetables to the sides of the pan.
4. Add butter and minced garlic to the center of the skillet. Cook for around 30 seconds until fragrant, then mix into the vegetables.
5. Return the chicken to the skillet, drizzle with balsamic vinegar, and toss everything to combine. Cook for an additional minute to warm through.
6. Adjust seasoning with salt and black pepper as needed. Serve hot.