In a large heavy pot on medium high heat one tablespoon of olive oil. Add the onions; cook until tender and lightly browned; about 3 minutes. Salt and pepper to taste. Add the collard greens; cook until vibrant green; about 3 minutes. Add the garlic, cumin, oregano, red pepper flakes; stir to combine. Add the spinach and cook until wilted; about 2 minutes. Turn off heat.
Coat a medium cast iron skillet with remaining olive oil (or cooking spray to reduce calories). Transfer the mixture to the skillet leaving excess liquids behind. Scatter mushrooms on top. Make four wells in the mixture; gently crack eggs directly in to wells. Bake until the eggs are set; about 7-10 minutes.