Easy Baked Ham and Egg Cups

Preheat the oven to 375 degrees F.
In a large sauté pan or skillet, sauté scallions and mushrooms in butter over medium heat; stirring occasionally, until the mushrooms are tender and softened, approx. 8-10 minutes.
Remove the pan from heat; stir in the tarragon and sour cream; season to taste with salt and pepper.
Gently press one slice of ham into each of the 12 (oiled) muffin cups, allowing the edges of each ham slice to protrude slightly above each muffin tin cup.
Divide prepared mushroom mixture among the ham cups, then crack one egg on top of the mushroom mixture into each cup.
Bake, uncovered, on the middle rack of the preheated oven until whites are cooked but yolks are still soft, approx. 12-14 minutes, or to desired doneness; remove from oven.
Let the ham and egg cups rest for a couple minutes, then use a butter knife to loosen each cup from the muffin tin edges; carefully lift the ham and egg cups from the muffin tin, placing them onto a cooling rack.
To serve, garnish each ham and egg cup with a dollop of sour cream and sliced scallions, as desired. Serve at once.