Rinse the sushi rice under cold water until clear. Soak for 45-60 minutes. Combine soaked rice with water in a saucepan, add salt, boil, then simmer for 10-12 minutes until tender. Fluff and cool.

Boil a large pot of water. Add 3-4 Napa cabbage leaves and boil for 2-3 minutes until soft. Transfer to cold water. Repeat for remaining leaves.

Heat 0.5 tablespoon of oil in a skillet. Sauté chopped onions, minced ginger, and garlic for 2-3 minutes. Add diced carrots, bell peppers, and mushrooms, cooking until softened. Drizzle in tamari and seasonings, cooking for another 1-2 minutes.

In a mixing bowl, combine cooked sushi rice with the sautéed vegetable mixture. Gently stir and adjust seasoning.

Lay a cooked cabbage leaf flat, spoon 1.5-2 tablespoons of filling in the center. Fold the sides over, rolling tightly. Place seam-side down on a plate.

Heat 1 teaspoon of oil in a skillet. Sear cabbage rolls for 3-4 minutes on each side until golden brown.

In a saucepan, heat 1 tablespoon of sesame oil. Add minced ginger and garlic, cook for 1-2 minutes. Mix in tamari, rice vinegar, maple syrup, and water. Stir in cornstarch slurry; thicken for 3-4 minutes.

Serve the cabbage rolls on a platter, drizzling with sauce and sprinkling sesame seeds on top. Enjoy warm.