Preheat oven to 450°F (232°C).
Cut the cauliflower into small, nugget shaped pieces. The smaller the better. I also prefer to remove the florets from the stems. The stems can be used in this recipe, they taste equally as delicious.
In a large bowl whisk the cornstarch, salt and pepper together. Then add the water and gochujang paste in. Whisk until a smooth batter forms. This will be on the thinner side.
Pour the cauliflower in the bowl and toss to coat. Slowly pour the breadcrumbs into the bowl. Do this in about 4 batches. Add a little, then stir to coat. Repeat until all breadcrumbs have been used. This helps to equally distribute the breadcrumbs.
Place them on a parchment lined baking sheet and bake for 25 minutes. Optional: before baking spray with cooking oil spray to get them extra crispy.
While it bakes prepare the sauce. In a measuring cup or bowl whisk the ingredients, except the slurry, together. Prepare the slurry on its own and then add it to the sauce to prevent clumping.
Pour the sauce into a large nonstick pan and simmer over medium low heat for 5 minutes. Sauce should be thick and glaze like.
Once the cauliflower is done immediately pour into the pan and toss to coat.
Sprinkle with sesame seeds and green onion. This dish is best enjoyed hot and warm. If you prefer your cauliflower stay completely crispy you can place it back in the oven or dip the cauliflower in the sauce.