Heat a stovetop pressure cooker over medium heat or set an electric pressure cooker to sauté; add the sesame oil if using. Add the onion, carrot, and sweet potato and sauté for 2 minutes. Add the garlic and 1 tablespoon of the sesame seeds and sauté for mother minute. Add the tofu, tamari, vinegar, and stock.
Lock the lid on the cooker. Bring to high pressure and cook for 3 minutes (set your electric pressure cooker to cook for 3 minutes on high pressure). Quick release the pressure. Carefully remove the lid, tilting away from you.
Add the peas and lock the lid back on. Bring to low pressure; cook for 1 minute. (If you do not have a low pressure option, lock the lid on and let sit for 2 to 3 minutes.) Quick release the pressure. Remove the lid, carefully tilting away from you.
Stir in the pepper sauce and tahini, if using. Garnish with the remaining 1 tablespoon sesame seeds and the chopped green onions and serve.
Variations: Use broccoli florets or 1-inch pieces of green or wax beans instead of the peas. Cook at low pressure for 2 minutes with a quick release.