1. Heat 2 teaspoons vegetable oil in 12-inch skillet over medium-high heat until shimmering. Add mushrooms and 1/2 teaspoon salt; cook, stirring occasionally, until pan is dry and mushrooms are browned, 6~8 minutes. Transfer mushrooms to large plate and let cool completely. Heat remaining 2 teaspoons vegetable oil in now-empty skillet until shimmering. Add fennel and 1/4 teaspoon salt; cook, stirring occasionally, until just browned and crisp-tender, 3~4 minutes. Transfer to plate with mushrooms.

2. Whisk olive oil, vinegar, shallot, 1/2 teaspoon salt, and 1/2 teaspoon pepper together in bowl. Transfer cooled rice to large bowl. Add vegetables and dressing; toss to combine. Let stand for 10 minutes.

3. Add 1/2 cup walnuts, tarragon, and 1 tablespoon parsley; toss to combine. Season with salt and pepper to taste. Sprinkle with remaining walnuts and remaining 1 tablespoon parsley; serve.

Serves 6~8