Start by gathering all your ingredients. This ensures you have everything ready and simplifies the process.

Dice the onion, jalapeño, and garlic finely.

In a large mixing bowl, combine the diced tomatoes, onion, cilantro, lime juice, jalapeño, garlic, salt, cumin, and black pepper. Stir until everything is well mixed.

Taste and adjust seasoning if necessary.

While the salsa rests, prepare your canning jars by sterilizing them.

Carefully spoon the salsa into the prepared jars, leaving about half an inch of headspace.

Wipe the rims of the jars to ensure a proper seal. Place the lids on and screw the rings until they are fingertip-tight.

Process the jars in a boiling water bath for about 15 minutes.