In a large bowl, combine the flour, salt, and instant yeast. Then add the olive oil and water. Stir to combine, then knead with your hands (or use a kitchen machine with a dough hook) until it's a smooth dough. If the dough is too sticky, add more flour; if it's too crumbly, add more water.
Cover the bowl with a clean kitchen towel and let it sit in a warm place until the dough doubles in size (for about 2 hours).
Preheat the oven to 200 °C or 400 °F.
Roll out the dough on a lightly floured parchment paper, like you would with pizza, and brush the dough with olive oil. Sprinkle salt and sesame seeds on top.
With a pizza cutter, cut the dough in strips. Transfer the parchment paper with the grissini onto a baking sheet. Twist each of the strips.
Bake the sesame grissini in the oven for about 15 minutes until golden and crispy.