Heat a clean heavy flat pan or a cast iron pan on a medium heat. Add the sesame seeds and roast them while stirring constantly until a little golden brown. Make sure you stir it constantly so they don't burn. You don't want to over roast them.
Transfer them on to a plate or a bowl to cool down. Now put then in the food processor along with olive oil and process them into a paste by scraping the sides. Add more olive oil if the desired consistency hasn't reached.
Process it more if you want a smooth paste. A little bit of grits are okay specially for recipes like hummus and baba ghanoush as it will be mixed with chickpeas and processed again.
Serve it in a air tight container and refrigerate. It should last you for at least a couple of months.