Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Trim the woody ends off the asparagus spears and cut the stalks into 1-inch pieces.
Dice the chicken breast into small, bite-sized cubes to ensure even cooking.
In a mixing bowl, toss the chicken and asparagus with the lemon juice, minced garlic, dried oregano, sea salt, and black pepper.
Spread the mixture in a single layer on the prepared baking sheet and roast for 12-15 minutes until the chicken is cooked through and the asparagus is tender.
While the chicken roasts, warm the corn tortillas in a dry skillet over medium heat for 30 seconds per side until pliable.
In a small ramekin, whisk the non-fat Greek yogurt with a teaspoon of water or extra lemon juice to create a smooth, pourable consistency.
Divide the roasted chicken and asparagus evenly between the tortillas and finish with a drizzle of the herb yogurt sauce.