Place eggs in a saucepan and cover them with water. Bring the water to a boil gently. Cook the eggs for twelve minutes until fully hard-boiled and firm.

Transfer the boiled eggs into a bowl filled with cold water. Let them cool completely before peeling carefully. Remove all shell pieces for smooth pickled eggs.

In another saucepan, combine vinegar, water, sugar and salt. Add peppercorns, mustard seeds, garlic, bay leaves and red pepper flakes. Stir well and heat until everything blends nicely.

Add sliced onion and beet into the warm vinegar mixture. Simmer gently for three minutes until the vegetables soften slightly and release beautiful flavor and color.

Place peeled eggs carefully into a clean glass jar. Pour the warm pickling liquid over the eggs slowly. Make sure all eggs stay fully covered inside the jar.

Seal the jar tightly with the lid. Place the jar inside the refrigerator for at least two days before serving. Longer chilling gives stronger and deeper flavor.

Remove the eggs from the jar using a clean spoon. Slice and serve cold with salads, sandwiches or crackers for a delicious and tangy homemade snack.