To make the rice. Heat the sesame seeds in a small skillet over medium heat, shaking the pan occasionally for about 5 minutes. Remove the seeds when they darken and become fragrant.
Add the water to a medium size pot. Bring to a low boil and then add the rice and sesame oil. Stir to combine and then place the lid on the pot and turn the heat down to the lowest setting possible. Allow the rice to cook ten minutes on low and then turn the heat off completely and let the rice sit on the stove, covered for another 20 minutes (don't take any peeks inside!). After 20 minutes remove the lid and fluff the rice with a fork and stir in 1-2 tablespoons toasted sesame seeds. Note that rice can cook differently for everyone, this is just what works for me.
While the rice cooks start the steak. Slice the flank steak against the grain into 1/4-inch pieces and add to a medium size bowl. To the bowl add the 1 tablespoon of cornstarch and toss well. Set aside.
Mix the remaining cornstarch with 2 tablespoons cold water until there are no lumps. Heat 1 tablespoon of peanut oil in a small sauce pot over medium-low heat. Add the ginger and garlic and sauté about 1 minute. Add the soy sauce, water, hot chili oil, brown sugar, and crushed red pepper. Whisk to combine. Bring the sauce to a boil and whisk in the cornstarch mixture, boil for about 3 minutes. Remove from the heat and set aside.
Heat a large skillet or wok over medium high heat, add 1 tablespoon of oil. Once hot add the red pepper, orange pepper and zucchini. Stir fry for about 5 minutes or until the veggies are soft and tender, then remove from the pan and place on a plate. Return the skillet to medium high heat and add another tablespoon of oil. Grab the steak and add to the skillet, shaking off any extra cornstarch as you place it in the pan. Stir fry for about 2-3 minutes, until just barely cooked through. Now carefully pour the sauce into the skillet. Add the peppers back in and bring the sauce to a boil. Boil 3-4 minutes or until the sauce has thickened and is coating the steak and peppers (the sauce must come to a boil for it to thicken). Stir in the green onions and serve over the toasted sesame rice, sprinkle with toasted sesame seeds if desired.