Cut the corn from the cobs and set the corn aside. Pour the stock into a large pot and add the cobs to the stock. Place the stock on the back burner reduce it to the barest simmer.
Once the oil is shimmering, add the onion and a generous pinch of salt. Sauté until the onion is just translucent. Stir in the garlic and sauté until fragrant
Stir in the arborio rice and toast the rice until it begins to crackle and starts to smell nutty. Pour in the vermouth and stir until it is absorbed by the rice.
Add two ladlesful of the simmering stock to the rice. Stir frequently until the stock is fully integrated. Add two more and repeat until the rice is creamy and tender.
When the rice is nearly done, stir in the corn and cook for an additional 3-5 minutes or until the corn is heated through.
Divide the risotto across four bowls and top each with 4-5 shishito peppers, a pile of mustard greens, and a sprinkling of sesame seeds.