1. Cut cauliflower into bite-size florets, place in a pot, cover with water and bring to a boil. Cook for about 8-10 minutes, until fork tender. Drain and let cool.
2. To get perfect hard-boiled eggs, place them in a saucepan and cover with cold water. Make sure the tops of the eggs are covered by at least an inch of water. Bring the water to a full boil, cover and remove from the heat. Let stand for 15 minutes. Then place the eggs in a bowl of cold water.
3. Meanwhile, cook bacon. Place it on the bottom of a cold skillet, cook on medium-high until crispy. Drain on paper towels and crumble.
4. Chop the eggs. Finely chop onion.
5. In a small bowl, combine mayonnaise, lemon juice and mustard.
6. In a large bowl, combine cauliflower, eggs, onion, half of the bacon (if you use), peas, mayonnaise and stir.
7. Put in fridge until serving. The longer it chills, the better the flavor.
8. Serve topped with freshly ground black pepper and bacon.