1. Heat oven to 375 degrees F.
2. Season pork with 1/4 teaspoon each of the salt and pepper. In a large ovenproof skillet over medium-high heat, brown pork on all sides in 2 teaspoons hot oil.
3. Transfer pan to oven and roast 6 to 7 minutes. Remove pan from oven; add pear wedges and cook over medium-low heat 4 minutes, stirring occasionally, or until golden.
4. Add water and vinegar and cook, stirring frequently and turning pork halfway through cooking time, 5 minutes, or until liquid is reduced. Remove pork from skillet; cover loosely with foil and let rest.
5. Meanwhile, bring a large saucepot filled with salted water to a boil; add Brussels sprouts and cook 2 minutes, or until just tender and still bright green.
6. Drain and toss gently with remaining oil, salt and pepper. Slice pork and serve with pears and Brussels sprouts; drizzle with pan juices.