How do you thicken a sauce with no flour or cornstarch?

1. Reduce the sauce: Simmering a sauce over medium heat will cause the water content to evaporate, resulting in a thicker consistency.

2. Add a roux: A roux is a mixture of equal parts flour and fat (usually butter) that is cooked until it becomes a paste. It can then be added to a sauce to thicken it. If you don't want to use flour, you can make a roux using another starch, such as cornstarch or arrowroot powder.

3. Use a beurre manié: A beurre manié is a mixture of equal parts softened butter and flour that is kneaded together until it forms a paste. It can be added to a sauce in the same way as a roux.

4. Add an egg yolk: Egg yolks contain lecithin, which is an emulsifier that can help to thicken a sauce. To use an egg yolk to thicken a sauce, whisk it together with a little bit of water or cream and then add it to the sauce. Be sure to add the egg yolk slowly and whisk constantly to prevent it from curdling.

5. Add grated cheese: Grated cheese can help to thicken a sauce by adding fat and protein. It can also add flavor and richness to the sauce.

6. Add puréed vegetables: Puréed vegetables can help to thicken a sauce by adding fiber and starch. They can also add flavor and nutrients to the sauce.

7. Add a cornstarch slurry: A cornstarch slurry is a mixture of cornstarch and water that is added to a sauce to thicken it. To make a cornstarch slurry, mix together equal parts cornstarch and water until the cornstarch is dissolved. Then add the slurry to the sauce and whisk constantly until the sauce has thickened.

8. Add an arrowroot slurry: An arrowroot slurry is a mixture of arrowroot powder and water that is used to thicken a sauce in the same way as a cornstarch slurry. Arrowroot powder is a starch that is derived from the root of the arrowroot plant. It is a good thickener for sauces because it does not have a strong flavor and it does not cause the sauce to become cloudy.

9. Add tapioca starch: Tapioca starch is a starch that is derived from the root of the cassava plant. It is a good thickener for sauces because it does not have a strong flavor and it does not cause the sauce to become cloudy.

10. Add Xanthan gum: Xanthan gum is a polysaccharide that is used as a thickener in many commercial food products. It is a very effective thickener and it does not have a strong flavor.