Preheat your oven to 400 degrees F.
Combine all Lemon Garlic Marinade ingredients in a freezer-size sealable bag and reserve 2 tablespoons for later use on vegetables. Add the chicken thighs into the bag, seal it tightly, and turn it gently to coat all pieces well in the marinade.
Line a large sheet pan with sides using foil and spray it lightly with cooking spray.
Place quartered potatoes onto one side of the baking sheet, drizzle with the reserved marinade, and sprinkle with salt before tossing them together until evenly coated.
Bake the potatoes alone at 400 degrees F for about 15 minutes until they start softening.
After 15 minutes of baking, remove the pan from the oven; push potatoes aside and toss fresh broccoli florets in more reserved marinade before placing them next to potatoes along with seasoned chicken arranged in a single layer.
Return everything back into the oven uncovered; bake until chicken reaches safe internal temperatures while simultaneously mixing yogurt sauce ingredients together in a bowl - refrigerate until serving!