Pat each salmon filet with a paper towel to remove excess moisture. Set aside.
Prepare the homemade teriyaki sauce by adding the soy sauce, maple syrup, minced garlic, grated ginger, and sriracha (if using) into a bowl. Whisk the ingredients together.
Add the salmon filets to a plastic bag or a deep bowl and pour half of the teriyaki sauce over the salmon. Set the rest of the teriyaki sauce aside for later. Be sure the salmon is submerged in the teriyaki sauce and let it marinate for 30 minutes in the refrigerator.
Line a baking sheet with parchment paper and preheat the oven to high broil.
Remove the salmon from the marinade and let any excess teriyaki sauce drip from each salmon filet. Place the salmon filets on the baking sheet skin-side down.
Place the salmon in the oven and broil for 8 minutes, checking the salmon after 6 minutes to be sure it’s not burning.
Meanwhile, pour the remaining teriyaki sauce into a small saucepan and bring to a gentle boil over medium heat. Add warm water and cornstarch to a small bowl and whisk the two ingredients together and then add it to the saucepan. Whisk the cornstarch into the sauce until it thickens. Remove the sauce from heat and set aside.
When the salmon is flakey and cooked, remove it from the oven. Let the salmon rest for 5 minutes.
Plate the salmon with rice and top with the remaining teriyaki sauce and enjoy.