Grate the cucumber using a box grater, then wrap in a clean kitchen towel and squeeze out as much moisture as possible. Combine with Greek yogurt, lemon juice, olive oil, minced garlic, fresh dill, salt, and pepper. Stir well and refrigerate for at least 20 minutes.

Combine halved tomatoes, diced cucumber, and sliced red onion in a bowl. Drizzle with red wine vinegar and a pinch of salt. Toss gently and set aside.

Rinse quinoa thoroughly under cold water using a fine-mesh strainer. Add to a pot with 2.5 cups of water and a pinch of salt. Bring to a boil over medium-high heat, reduce to a low simmer, cover, and cook for 15 minutes. Remove from heat and let sit covered for 5 minutes without lifting the lid. Fluff with a fork and season while still hot.

Cut chicken into 1-inch pieces and toss in a bowl with harissa, honey, salt, and pepper until evenly coated.

Heat olive oil in a skillet over medium heat. Add the marinated chicken and cook for 7 to 10 minutes, stirring occasionally, until cooked through and slightly caramelized. Keep heat at medium to prevent the honey from burning. Cook to an internal temperature of 165 degrees F.

Assemble bowls: start with a base of quinoa, add the harissa-honey chicken, top with Greek salad, drizzle generously with tzatziki, and finish with crumbled feta and fresh mint.