Red Curry with Vegetables

1 14-ounce package extra-firm tofu, rinsed, patted dry and cut into 1-inch cubes

1 pound sweet potato, cut into 1-inch cubes

1 14-ounce can lite coconut milk

1/2 cup vegetable broth or reduced-sodium chicken broth

1-2 teaspoons red Thai curry paste

1/2 pound green beans, trimmed and cut into 1-inch pieces

1 tablespoon brown sugar

2 teaspoons lime juice

1/2 teaspoon salt

1/3 cup chopped fresh cilantro

1 lime, quartered