Place raw buckwheat in a medium pot. Add ½ tsp salt and the water.
Bring to a boil over high heat. Turn down heat to a simmer, cover pot.
Cook until water is absorbed, and buckwheat is done.
Remove from heat and cool.
Dice tomatoes, cucumbers, sweet pepper, and lettuce. Chop onions.
Place all vegetables in a salad bowl.
Add the lemon juice, olive oil, and remaining salt.
Stir in buckwheat until well mixed.