Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Prepare the artichoke by slicing off the top inch, trimming the stem, and cutting it in half vertically. Use a spoon to scoop out the fuzzy choke from the center.
Place the artichoke halves in a steamer basket over boiling water and steam for 15 minutes until the heart is slightly tender.
While steaming, season the chicken breast with half of the olive oil, sea salt, black pepper, and dried oregano.
Remove the artichokes from the steamer, pat dry, and brush with the remaining olive oil and seasonings.
Place the artichokes (cut side down) and the chicken breast on the prepared baking sheet.
Roast for 18-20 minutes, or until the chicken reaches an internal temperature of 165°F and the artichoke leaves are golden and crispy.
In a small bowl, whisk together the Greek yogurt, lemon juice, and minced garlic to create the aioli.
Serve the roasted artichoke and chicken hot with the lemon-garlic aioli on the side for dipping.