It will cost a few dollars and take a little bit of time, but this salsa is super easy to make and is very good for you!
6 roma tomatoes, seeded
1/4 yellow onion
1 jalapeno, seeded
1 bunch cilantro
2 cloves garlic
Finely chop all veggies and squeeze juice from the lime. Add spices to taste (I'd guess about 1/4 tsp each.)
For best flavor, let sit in the refrigerator for a few hours to chill.
Of course, this is just what I did. Feel free to add more or take something out. Have fun and experiment with your own ingredients!