In a bowl, combine water, tamari, rice vinegar, maple syrup, garlic, sesame oil and ginger root. Whisk to combine.
Add arrowroot or cornstarch and whisk to prevent clumping.
Add cauliflower florets to liner of Instant Pot or Electric Pressure Cooker (EPC).
Pour liquid mixture over the top and gently toss to coat cauliflower with sauce.
Seal Instant Pot/EPC. Set to Manual High Pressure for 4 minutes. Once pot has come to pressure, cooked for 4 minutes, then allow a 5 minute Natural Pressure Release (NPR) with the keep warm/cancel button illuminated. Carefully release any remaining pressure.
Turn Instant Pot/EPC to saute. If yours has an adjustment for saute level, use the high setting. Saute for 3 to 5 minutes while frequently stirring. This allows the sauce to thicken.
Toss with 1 Tablespoon of the sesame seeds. Use remaining sesame seeds and cilantro or green onions to top once the dish is in a serving bowl.