1. Spray a non-stick pan with cooking spray and heat on medium. Once the pan is hot, place banana halves cut side down in the pan with the walnuts. Fry until bananas are caramelized and walnuts are toasted, 1-2 minutes. Flip bananas over and stir walnuts. Fry for an additional 1-2 minutes. Remove from heat.
2. Heat dark chocolate chips in microwave safe dish in 15 second intervals until melted, stirring after each interval.
3. Add Greek yogurt evenly into 2 small bowls. Top with bananas and walnuts. Drizzle with dark chocolate. Serve.