Cook the quinoa: Add rinsed quinoa, broth, and salt to a saucepan. Bring to a boil, reduce to a low simmer, cover, and cook for 15 minutes. Turn off heat and let it sit, covered, for 5 minutes.
Fluff with a fork.
Make the dressing: In a small bowl or jar, whisk olive oil, lemon zest and juice, garlic, Dijon, honey, salt, and pepper until smooth. Taste and adjust seasoning.
Season the shrimp: Pat shrimp dry. Toss with olive oil, smoked paprika, garlic powder, cumin, red pepper flakes (if using), salt, and pepper until well coated.
Cook the shrimp: Heat a large skillet over medium-high.
Add shrimp in a single layer. Sear 1.5–2 minutes per side until pink and opaque. Do not overcook.
Remove to a plate.
Prep the veggies: While the shrimp cooks, chop tomatoes, cucumber, bell pepper, and onion. Roughly chop herbs.
Toss the base: In a large bowl, combine quinoa, spinach, half the herbs, and half the dressing. Toss until the greens just begin to wilt.
Assemble bowls: Divide the quinoa mixture among bowls.
Top with shrimp, tomatoes, cucumber, bell pepper, onion, avocado slices, and any optional toppings like feta or seeds.
Finish and serve: Drizzle remaining dressing over the top. Garnish with the rest of the herbs. Serve warm or at room temperature.