Peel and slice radishes into matchstick pieces. Place pieces in a colander and toss in salt.
While the radishes sit, whisk together the sesame oil, vinegar, lemon juice, and garlic. Pour radishes and brine in a small jar, close, and shake until all radish pieces are coated. Let them sit in the refrigerator for at least 1 hour.
In the meantime, combine the spinach, beets, and quinoa in a serving bowl. Top with marinated radishes and a sprinkle of the brine, serve, and enjoy!
Notes
Sodium is not accurate in nutrition facts, since you will not be using all the radishes and their brine for the salad.