Preheat the oven to 400F. Fill a large pot with water and place over medium-high heat to start heating up.
Cut the salmon into 1-inch cubes and place in a medium bowl. Add the remaining ingredients: olive oil, dijon mustard, lemon zest, garlic, salt, dried parsley, and sumac. Stir to combine and set aside.
When the water has come to a boil, add the quinoa, turn the heat to medium low, and let it cook for 5 minutes. Then add the couscous to the pot and cook both together for an additional 8-12 minutes, until both are tender. Drain any extra water and transfer the quinoa/couscous to a large bowl.
Peel and thinly slice the carrots. Place on a baking sheet and toss with olive oil, salt, and pepper. Transfer to the oven and roast for 10-15 minutes, until the carrots are cooked through.
While the quinoa/couscous and carrots cook, prepare the dressing. Add the tahini, lemon juice, miso paste, honey, and garlic to a bowl. Stir until smooth. The mixture will be quite thick. Add the cold water and stir to combine. If the mixture is still too thick, continue to add water until your desired consistency is achieved.
Add about 2/3 of the dressing to the quinoa and couscous. Stir until combined. Add the black sesame seeds and stir in. Set aside.
Heat a large pan (I prefer cast iron here) over medium-high heat. Add a glug of olive oil when the pan is hot. Place the salmon bites in the pan, rotating each piece every minute until the bites are cooked through on each side.
To assemble the bowls, add the miso sesame couscous, carrots, cucumbers, tomatoes, and salmon bites. Top with the remaining tahini dressing and enjoy!