Take cornstarch in a small bowl.
1.5 Teaspoon Corn Starch
Add 1-2 teaspoons of water and make a smooth paste and set it aside.
Heat water in a pan. Add sugar in it and stir till the sugar completely dissolves in the water.
2 Tablespoon Sugar, 1/3 Cup Water
Very finely chop the garlic cloves. You can also make a paste using a mortar & pestle. Add this minced garlic to the pan along with crushed & dried red chili flakes. Also add vinegar and salt and simmer for 2-3 minutes.
1 Tablespoon Crushed and Dried Red Chili Flakes, 1-2 Garlic Cloves, minced, 1.5 Tablespoon Vinegar, 1/2 Teaspoon Salt
Add the cornstarch paste to the sauce and stir.
You will see that the sauce starts congealing when you add cornstarch.
Simmer for 1 minute on low flame as the sauce thickens.
Thai sweet chili sauce is ready. Let it cool down and then refrigerate it in an airtight jar for later use. You can use it as a dip for snacks and finger foods like spring rolls and potato wedges.