If you want to learn how to thicken sauce without flour or cornstarch, here are several effective alternatives:

1. Reduce the Sauce
   Simmer the sauce over low heat, allowing the liquid to evaporate. This naturally thickens the sauce while intensifying its flavor. Stir occasionally to prevent burning.

2. Use Pureed Vegetables
   Blend cooked vegetables (like carrots, potatoes, or cauliflower) and stir them into the sauce. They act as natural thickeners and add extra nutrients.
   Example: Pureed tomatoes or roasted red peppers work well for tomato-based sauces.

3. Add Mashed Legumes
   Mash or puree beans (e.g., white beans or chickpeas) or lentils, then mix them into the sauce. This method is a great option when exploring how to thicken sauce without flour or cornstarch in savory dishes.

4. Incorporate Nut Butter
   Stir in a small amount of peanut butter, almond butter, or tahini for a creamy, thick texture. This method is excellent for savory sauces with a rich flavor profile.

5. Egg Yolks
   Whisk egg yolks into a small amount of warm sauce, then gradually mix the yolk mixture back into the main sauce. This technique is perfect for creamy sauces but requires gentle heating to avoid scrambling.

6. Add Coconut Cream or Dairy
   For creamy sauces, use heavy cream, sour cream, Greek yogurt, or coconut cream to thicken while adding richness. This is a simple and effective way to master how to thicken sauce without flour or cornstarch.

7. Use Ground Nuts or Seeds
   Finely ground almonds, cashews, or sunflower seeds can be stirred in to thicken sauces, especially in curries or gravies.

8. Gelatin or Agar-Agar
   Dissolve unflavored gelatin or agar-agar in warm water and mix it into the sauce. These thickeners work well for thicker, set sauces and are ideal for exploring how to thicken sauce without flour or cornstarch.

9. Arrowroot Powder
   If avoiding cornstarch specifically, arrowroot powder is a gluten-free, grain-free alternative. Dissolve it in cold liquid before adding it to the sauce for a smooth consistency.

10. Psyllium Husk or Chia Seeds
    Add a tiny amount of psyllium husk or ground chia seeds. These absorb liquid and create a gel-like consistency. Use sparingly to avoid a gummy texture while learning how to thicken sauce without flour or cornstarch effectively.