Over medium-low in a small saucepan heat the sesame oil. Add the garlic, ginger and some cayenne pepper for extra heat (this is optional, I like mine spicy).
Stir and continue adding the vegetable broth, sugar, tomato paste and soy sauce. Continue cooking over medium-low heat for about 10 minutes.
In a small cup dissolve the corn starch with 2 tablespoons of water. Next, whisk until a milky consistency is obtained.
Reduce heat to low. Slightly pour the corn starch into the sauce and whisk continuously, continue cooking for about 10 minutes or until it thickens.