You can roast the sesame seeds in the oven or in a frying pan, stirring constantly until lightly browned.
Preheat your oven to 175°C (350°F).
Spread the sesame seeds on a rimmed baking sheet and toast in the oven until lightly browned, stirring occasionally. Be careful not to burn them.
Pour the roasted sesame seeds into a dish to stop the cooking.
Allow to cool slightly before pouring into a blender or food processor.
Blend at maximum speed, stopping from time to time to scrape the edges and allow the blender motor to cool if necessary (it should not heat up).
Blend until smooth and creamy.
The process starts with a powder, then becomes a thick paste. By continuing to blend, the sesame seeds release their oil and the texture becomes smooth and creamy.
You can add a little oil to help the food processor. I don't use any, just blend, pausing, until I get a smooth, creamy, fairly runny texture.
Add a pinch of salt and blend one last time.
Pour the tahini into a jar with a tight-fitting lid and store in the cupboard for up to 1 month, or in the refrigerator for up to 3 months.