Combine the vegetables except the spinach into the slow cooker. Combine the sauce ingredients into a bowl and then toss the vegetables with the sauce until coated.
Adjust the slow cooker to high. Cook for 2 ½ - 3 hours, or until vegetables are soft. You can also cook on low for 5 - 6 hours. When the vegetables are cooked through, remove the lid and stir in the spinach until wilted.
If using an Instant Pot Pressure Cooker, cook for 13 minutes.
Garnish with cilantro leaves, green onions and toasted sesame seeds.