For the salad, in a large bowl, combine the brown rice, carrots, cucumber, onion, radishes, celery, parsley, and thyme.
For the dressing, in a small container, combine the olive oil, lemon juice, honey, vinegar, mustard, garlic, salt, and pepper. Pour the dressing over the brown rice salad, toss to combine very well, turn into a serving platter and serve at room temperature.
Notes
There are a number of brown rice varieties easily available these days, from brown basmati to brown jasmine, and of course, plain regular brown rice works out just perfectly.
Try other grains in place of the rice, such as quinoa, bulgur, farro, or wheat berries. Farro and wheat berries are denser, so use 2 cups of those grains instead of the 4 cups of rice.
Play around with the vegetables! Just make sure to slice them thinly or cut them into small dice, so they blend in with the rice easily, and the salad can be scooped up with a fork. Try summer squash, zucchini, bell peppers, tomatoes, lightly cooked chopped broccoli, or sliced asparagus.