Cook the quinoa by bringing the water or vegetable broth to a boil in a medium saucepan. Add the quinoa, reduce the heat, cover, and simmer for about 15 minutes, or until the liquid is absorbed and the quinoa is fluffy.
While the quinoa is cooking, heat a skillet over medium-high heat. Season the salmon fillets with salt and pepper. Cook the salmon for 4-5 minutes on each side, or until fully cooked and browned.
In a bowl, toss the cherry tomatoes and red onion with olive oil and lemon juice. Season with salt and pepper.
To assemble, divide the quinoa into bowls. Top each bowl with a salmon fillet, avocado slices, tomato-onion mixture, and garnish with fresh parsley.
