Cornstarch (Best Option)
1 tablespoon cornstarch per 2 tablespoons all-purpose flourCornstarch is a pure starch extracted from corn, which makes it an excellent thickening agent for liquids like stew. It gelatinizes at around 144-162°F (62-72°C), forming a smooth, translucent gel that thickens the broth without cloudiness. This property helps maintain the visual appeal and mouthfeel of the stew. When substituting, use half the amount of cornstarch compared to flour because cornstarch has roughly twice the thickening power. To avoid a starchy taste or breakdown of the gel, it's best to add cornstarch slurry towards the end of cooking and simmer briefly.