Preheat oven to 400˚F.
Place thawed spinach in a clean kitchen towel and wring dry over a sink to remove all excess moisture.
Heat olive oil in an oven-proof medium pan over medium heat. Once hot, add onion, peppers and fresno. Cook until onions are translucent and peppers soften, about 5 minutes. Increase the heat and add the sweet potatoes. Cook until sweet potatoes begin to brown, stirring often. Season with harissa, salt and pepper and toss to coat. Add tomatoes and spinach and stir to combine.
Carve out four wells in the vegetable mixture. Into each well, add a splash of olive oil, about ½ teaspoon, and crack an egg into it. Season eggs with salt and pepper. Place the pan in the oven and bake until eggs are set, 5 to 8 minutes.
Remove the pan from the oven, drizzle with tahini, and garnish with parsley.