Season turkey with salt and pepper. In a large skillet, heat 1 tablespoon butter over medium-high. Add turkey and cook until cooked through, about 2 minutes per side, flipping once. Transfer to a plate and tent loosely with foil.
Add 2 tablespoons butter to skillet and reduce heat to medium. Add shallots, garlic, and thyme; season with salt and pepper. Cook, stirring occasionally, until shallots begin to soften, 6 minutes. Meanwhile, in a small bowl, whisk together broth, vinegar, and mustard. Add pears to skillet and cook, stirring occasionally, until beginning to soften, 4 minutes. Add broth mixture; cover and cook 5 minutes. Uncover, increase heat to high, and cook, stirring occasionally, until pears are tender and liquid is almost evaporated, 3 to 5 minutes. Return turkey to skillet, along with any juices. Add thyme, toss to combine, and serve.