Make the marinade base: In a bowl, whisk lemon juice and zest, olive oil, oregano, dill, coriander, smoked paprika, salt, and pepper.
Stir in the minced garlic.
Set up the slow cooker: Add sliced red onion to the bottom of the crock. Place chicken on top. Pour the marinade over the chicken and add the chicken broth around the sides.
Cook low and slow: Cover and cook on Low for 4–5 hours or High for 2–3 hours, until the chicken is tender and reaches 165°F in the thickest part.
Shred or slice: Transfer the chicken to a cutting board.
Shred with two forks or slice into strips. Toss the chicken back into the juices to soak up flavor.
Make the lemon-garlic yogurt sauce: Stir Greek yogurt, lemon juice and zest, olive oil, grated garlic, salt, and pepper in a small bowl. Thin with a splash of water if needed for drizzling.
Prep the base and toppings: Warm the rice or grain of choice.
Chop the tomatoes, cucumber, olives, and herbs. Crumble the feta.
Assemble the bowls: Add a scoop of rice or greens to each bowl. Top with a generous portion of chicken, a handful of tomatoes and cucumbers, a few olives, some red onion, and feta.
Drizzle with the yogurt sauce. Finish with fresh parsley or dill and an extra squeeze of lemon.
Adjust to taste: Sprinkle with a pinch of salt, pepper, and a light drizzle of olive oil if you like. Serve warm.