Line a baking sheet with parchment paper or aluminum foil (if using skin-on salmon give the foil a spritz of nonstick spray just in case) for easy clean up. Or spray the baking sheet with nonstick cooking spray.
In a small bowl add the teriyaki sauce, hoisin sauce, soy sauce, vinegar, sugar, garlic and red pepper flakes and mix until combined.
Place the salmon in a dish or large ziplock bag and pour 1/3 of the sauce on the salmon. place in the refrigerator and let marinate at least 30 minutes or up to 2 hours.
In a medium bowl add the broccolini and toss with the olive oil, salt and pepper.
In a small bowl add the cornstarch with 1 tablespoon of water and mix until you get a slurry.
Add the remaining marinade to a sauce pan and whisk in the cornstarch slurry and heat on medium heat until thickened about 3-4 minutes whisking so it doesn't burn.
Preheat the oven to 400 degrees and place the salmon strips onto the baking sheet along with the broccolini.
Bake for 12-15 minutes or until salmon is flakey and cooked through and reaches 145 degrees.
Brush with thickened sauce and garnish with sliced green onions or sesame seeds.
Video
Notes
You can use skinless or skin on salmon.
You can use 3-4 cups of broccoli instead of broccolini bunches if you prefer.
Store leftovers in an airtight container the refrigerator for 2 to 3 days.