Combine yeast, sugar, and ½ cup water in a bowl of a stand mixer. Let sit for 5-10 minutes, or until the yeast starts to foam or “bloom”. **if the yeast does not bloom, you may need to get fresher yeast**
Add remaining water, sugar, olive oil, tahini and rosemary, mixing on low to combine. Replace the paddle for the dough hook
Add flour and salt, one cup at a time, mix on low using the dough hook. Knead the dough until smooth and no longer sticky, adding more flour as needed.
Add the chopped garlic, olives, and walnuts, mixing to combine.
Transfer to a clean, oiled bowl. Cover with a clean, damp towel, and let rise until doubled in size, about 1 hour.
Preheat the oven to 350F. Line a baking tray with parchment paper.
Divide dough into 4 even pieces and braid.
Cover, and let rise for 20 minutes.
Drizzle with olive oil and sea salt.
Bake for 40-45 minutes, turning halfway through.
Enjoy!