Depending on how large your ingredients are, your batch size can vary. Just be sure to have a number of empty clean glass jars with tight lids to store the Sofrito. Remember when using Sofrito to season a dish, first open up the flavors by lightly frying it in olive oil (3 parts Sofrito - 1 part olive oil). Next add canned tomato sauce and thicken over light heat for 2-3 minutes. Now your Sofrito will be ready to be added to a dish as a seasoning or as a topping. Enjoy!
De-seed the bell peppers and chop into quarters. Separate the garlic head's cloves and peel each clove. Remove the peel from the onions, and chop into quarters.
Add half of all of the ingredients into a blender or large food processor. Add 1/4 cup of water, and blend until the ingredients are liquified and well incorporated. Be sure to check that there aren't any small whole chunks of ingredients. Pulse a number of times until smooth.
Pour the first half batch of sofrito into a large bowl and set aside.
Add the remaining half of ingredients into the blender/fp, and repeat step 2. If you have enough room in the blender/fp, add the first half batch from the large bowl back into the blender/fp to combine. Blend together for about 10 seconds to fully combine. If the two batches of sofrito don't fit back into your blender/fp, you can pour the second batch into the large bowl and combine together with a spoon.
Using a funnel (or very carefully and slowly), pour the sofrito from the blender/fp or large bowl into your small jars, leaving about an inch from the top (don't overfill the jars). Seal each jar tightly with an air-tight lid.
Keep one jar of Sofrito in your refrigerator, and freeze the remaining jars until needed for up to one year frozen. (You can freeze longer, but freshness may diminish over time even if frozen.)