Lemongrass paste is a prepared product that offers a shortcut to using this flavorful ingredient. Sometimes you can find it in a tube, other times in a jar and they are often found in the refrigerated produce section of the supermarket.   Read labels. Some contain fructose, and even garlic and onion, or other high FODMAP ingredients. Others contain vinegar and/or oil or a bit if sugar, but these are not a FODMAP issue.   We like Gourmet Garden Lemongrass. You might notice that it does contain whey derived from milk, but for the 1 teaspoon serving size the sugars total 0 g and the total carbs are 2 g. This will be tolerated by most.