Pierce potatoes with a fork. Microwave at 14 minutes on high. Remove from microwave and cool for 10 minutes.

Meanwhile, in a large skillet, bring 2 tbs water to a simmer over medium-high heat. Add spinach to pan and cook for two minutes, stirring often until spinach wilts. Cool for 5 minutes, then squeeze out excess water by placing spinach in paper towel. Chop spinach.

Preheat broiler. Cut the top-third off of each potato (length-wise). Remove pulp from potato, leaving a small "shell" inside the skin. Combine the potato pulp, yogurt, salt, pepper, pancetta, cheese and spinach in a large bowl and stir well to combine. Evenly fill potatoes with mixture. Place potatoes on a baking sheet and broil in the oven for 1 minute. Top with green onions and serve.