Green chutney (for samosa, dhokla, khandvi, chutney sandwich ....)

Ingredients

• 1 cup ( 200 g ) chopped coriander leaves ( or 150 g coriander leaves and 50 g mint leaves )
• 1 onion, chopped
• 2 teaspoon lemon juice
• 2 green chillies
• 1/2 teaspoon salt ( or to taste )
• 1/2 teaspoon sugar ( or to taste )
• 1/2 - inch piece ginger
• Extra 2 - 3 tablespoons water