Sauté the onion and garlic in 2 tbsp veggie broth in a small pan over medium heat*, for about 5-6 minutes, until softened.
*If you have an Instant Pot, you can sauté right in that with the sauté function. Just make sure to change it to the slow cooker function when you're done with this step.
~Leftovers will thicken up considerably. To reheat - you may want to add additional vegetable broth to thin it out.