In a salad bowl, whisk together olive oil, lemon juice, 1 tsp. thyme leaves, the mustard, 1/4 tsp. salt, and 1/4 tsp. pepper.
Add arugula and gently toss until leaves are coated with dressing. Add berries and gently toss. Divide among 4 salad plates. Crumble 1/2 oz. cheese on each salad. Sprinkle with remaining thyme and salt and pepper to taste.
Note: Nutritional analysis is per serving.