Add the olive oil to your large pot and turn on medium heat.
Cook the onion, pepper and garlic until done. If using roasted garlic, add that in at a later step.
Take a knife and place an “X” on the top of each tomato by gently slicing the skin.
In another pot, add your tomatoes to a pot of boiling water and blanch (cook) them for 1 minute.
Take the tomatoes out of the boiling water and now place them in an ice water bowl for a few minutes. Remove the skin from each tomato.
Place the tomatoes in a blender and pulse until smooth.
Add the tomatoes and all the seasonings to the onion mixture. Next, add the roasted garlic (if using it) along with your favorite cooked meat in this step. Cook on medium heat for a few minutes and then reduce the heat to simmer for at least an hour, stirring occasionally.
Gradually add the tomato paste and stir. Adjust the amount of paste according to how thick you want your sauce to be.
If you are adding the jalapeños, do this at the very end.