Rinse the quinoa. Rinse 1 cup quinoa under cold water for 20–30 seconds to remove bitterness. Drain well.
Cook the quinoa. In a medium pot, combine quinoa with 2 cups broth, a pinch of salt, and the zest of 1 lemon.
Bring to a boil, cover, reduce heat, and simmer 15 minutes. Turn off heat and steam 5 minutes. Fluff with a fork and squeeze in half a lemon.
Prep the herb dressing. In a bowl, whisk 1/4 cup olive oil, juice of 1 lemon, 1 minced garlic clove, 2 tablespoons finely chopped parsley, 1 tablespoon chopped dill, 1/4 teaspoon salt, and pepper.
Adjust lemon and salt to taste.
Mix the meatballs. In a large bowl, combine 1 lb ground meat, 1 egg, 1/3 cup breadcrumbs, 2 minced garlic cloves, 1 teaspoon dried oregano, 1/2 teaspoon ground cumin, 1/2 teaspoon salt, and pepper. Add 2 tablespoons chopped parsley. Mix gently until just combined.
Shape and sear. Roll into 16–20 small meatballs.
Heat 1–2 tablespoons olive oil in a skillet over medium-high. Sear meatballs 2–3 minutes per side until browned. Transfer to a sheet pan.
Finish in the oven. Bake at 400°F (205°C) for 6–8 minutes, or until cooked through (165°F/74°C for poultry).
Rest 3 minutes.
Chop the veggies. Dice cucumber, halve cherry tomatoes, and thinly slice red onion. Toss with a pinch of salt, pepper, and a splash of the herb dressing.
Assemble the bowls. Add a handful of spinach to each bowl. Top with a scoop of quinoa, a few meatballs, and the tomato-cucumber mix.
Spoon over the herb dressing.
Finish and serve. Add a dollop of yogurt or crumbled feta if you like. Sprinkle extra parsley, dill, and red pepper flakes. Taste and add more lemon or salt if needed.