根据下面的原料，写出制作vegetable salad的过程，注意使用这些词：fit then，after that，finally。词数不少于50。
Ingredients:
5 medium tomatoes (cut up)
1 cucumber (cut up)
2 onions (cut up)
Half a teaspoon of salt (add)
Some black pepper (add) (after 10 minutes)
2 teaspoons of olive oil (put)
1 teaspoon of vinegar (put) (mix it all up)