Preheat the oven to 400 degrees.
Slice the sweet potatoes down the middle and place them in a baking dish. Drizzle with avocado oil. Roast until fork tender and lightly golden.
While the sweet potatoes are roasting, heat avocado oil in a Dutch oven over high heat. Add the thinly sliced chicken pieces. Season with sea salt and black pepper.
Cook the chicken until browned and cooked through. Add a few tablespoons of Greek dressing , dijon mustard, and let it cook for a few more minutes. Make sure the internal temperature reaches 165 degrees.
While the chicken cooks, prepare the tzatziki. In a bowl, mix the Greek yogurt, chopped cucumber, fresh lemon juice, chopped garlic, chopped dill, olive oil, and sea salt. Taste and adjust lemon, salt, or garlic as needed.
Prepare the Greek salad vegetables by combining red onion, baby tomatoes, cucumber, and Greek dressing in a bowl.
To assemble the bowls, smash the roasted sweet potato at the bottom of each bowl. Top with chicken, Greek salad vegetables, and a generous spoonful of tzatziki.