Preheat oven to 425. Toss Brussels sprouts and pears with a drizzle of olive oil and salt and pepper. Spread in an even layer on a lightly greased baking sheet (or use parchment paper). Roast for 20-25 minutes or until golden brown.
Remove from oven. In a large bowl combine romaine lettuce with Brussels sprouts, cranberries and vinaigrette. Toss and serve.