Tasty, versatile and can be prepared in a matter of minutes.
Great with all kinds of Mexican food, especially as a topping for Mexican style beans with some sour cream, in wraps, or as a side dish for spicy meat and fish dishes, like my Yucatecan-Spiced Chicken Skewers.
I prefer to chop my tomatoes by hand, but like to throw all of the other ingredients into the food processor for a quick blitz to save on time, then just stir everything together and garnish with a few extra coriander leaves.
Serves four, 17 calories per serving.
2 tomatoes (around 190g for both) 
1/2 mild white onion (or use red, 60g) 
1 Serrano or Jalapeno (green) chilli, deseeded 
Small handful of fresh coriander (about 10g) 
Lime juice and salt to taste (I used the juice of 1/2 a lime, about 1/2 tbsp) 
Cut the tomatoes into small dice. Either finely dice the onions and chilli and chop the coriander; or chop them all roughly then pulse in a blender/food processor briefly until finely chopped, reserving a few leaves of coriander.
Mix all the ingredients together with a squeeze of lime and salt to taste and serve garnished with the coriander. Best served fresh, but can be made in advance, however if you're making in advance, don't add salt until the last minute as it will draw the moisture out of the other ingredients. Will keep in the fridge for a few days.