Preheat the oven to 425°F.
Add the chopped potatoes, cubed chicken breast, roasted red peppers, olives, and sliced shallot to a large baking tray or sheet pan.
Drizzle with olive oil, add the seasonings, and toss well to coat. Spread everything out into an even layer, making sure there’s no overlapping so it cooks evenly.
Bake for 20-25 minutes, stirring halfway through, until the potatoes are tender and the chicken is cooked through.
Meanwhile, whisk together the Greek yogurt, grated garlic, salt, pepper, and olive oil until smooth and creamy.
To serve, spread a scoop of the garlic yogurt onto individual plates or a large serving platter, then add the tray bake mixture over top.
Garnish with fresh herbs, a squeeze of lemon juice (optional), and another drizzle of olive oil!