Peel the skins off the tomatoes and garlic. If they are too hot, place them in cold water first.

Blend the tomatoes, onion, and garlic with 2 cups chicken broth (about 500 ml) in a blender until smooth.

Strain the mixture into a pot.

Bring to a boil over high heat, then reduce to low and simmer for 15 minutes. Stir occasionally, scraping any tomato from the sides.

Let the mixture cook until the tomatoes are well seasoned and most of the liquid has evaporated.

Add the remaining chicken broth and increase the heat. If needed, add chicken bouillon powder and salt to taste. Once it boils, cover and turn off the heat.

Microwave the chipotle peppers for 20 seconds and check them. They should become darker. You may need to microwave them for another 10 or 20 seconds.