In a medium sauté pan, heat olive oil over medium-high heat. Add diced onion and jalapeño, sautéing for about 5 minutes until the onion is soft and clear.
Include the minced garlic and continue to cook for another 1 to 2 minutes, until you can smell the garlic's aroma.
Carefully move the sautéed mixture to a blender. Pour in the broth, add the diced green chiles, cumin, salt, and black pepper.
Blend until the mixture is completely smooth. If the sauce is too thick, you can add a little more broth to reach your desired consistency.
Give the sauce a taste test and adjust the seasoning with extra salt, pepper, or cumin to suit your preference.