Place beets in a four-quart pot. Add enough water to cover beets completely. Add lemon juice and bring to a boil. Reduce heat to medium-low, cover pot and simmer for one hour.

Add honey and salt. Cook covered for 15 to 20 minutes longer, or until beets are fork tender. Drain well and cool completely.

Slice or shred beets and place them in a serving bowl. Toss in walnuts and red onion. Cover and refrigerate for one to two hours before serving. Serve chilled.