Toast 1/3 cup raw sesame seeds in a skillet until the seeds start getting golden with a few darker ones (don’t toast more than that or the seeds will turn bitter).
Combine 225g starter with 1 tablespoon brown sugar and 300g water in a bowl of a stand mixer. Add 1/2 teaspoon dry yeast, if using. Whisk until combined.
Add 200g whole grain Kamut and 370g King Arthur organic bread flour, sifted (I use a mesh to sift the flours straight into the bowl). Add 10g salt.
Using a spoon, roughly mix everything together until chunky. Add 1/3 cup toasted sesame seeds. Give it a couple of whirls with the spoon, then connect the bowl to a stand mixer.
Using a dough hook, knead the dough until it becomes uniform. I usually do 5-10 minutes.
Transfer dough to an oiled bowl, cover and place in a warm spot. I use a cooler with a fermentation space warmer for my day ferments. The temperature inside the chamber stays around 100ºF. Most favorite thing I own.
Once the dough doubled in size (could be anywhere between 2-6 hours), or at least raised dramatically, transfer it onto a floured surface and cut into 12 pieces. You might want to cover the dough pieces while shaping, they dry out fast.
Shape the dough into disks, making sure to pinch the seams tightly. Let the disks rest while you are working on the rest.
Poke a hole in each disk with your finger, then widen the opening with two fingers. Leave bagels to rest for 15 minutes or so (you can also let them rest longer than that to get a higher rise, I don’t bother). Preheat oven to 425ºF.