Bring 8 cups of low-sodium vegetable broth or water to a boil in a large saucepan. Add 2 cups of steel-cut oats and a pinch of salt. Reduce the heat and simmer uncovered, stirring occasionally, until the oats are tender and creamy, about 25-30 minutes.

While the oats are cooking, heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add 10 oz of sliced mushrooms and sauté until they are browned and tender, about 5-7 minutes. Season with salt and black pepper to taste.

Add 6 cups of baby spinach to the mushrooms in the skillet and cook, stirring, until the spinach is just wilted, about 2-3 minutes. Remove from the heat and set aside.

In a medium saucepan, bring water to a gentle simmer. Carefully add 4 large eggs and cook for about 6 minutes for slightly soft yolks (or adjust the cooking time to your preference for the yolk firmness). Once cooked, transfer the eggs to a bowl of cold water to stop the cooking, then peel.

Once the oats are ready, stir in the sautéed mushrooms and spinach. Adjust the seasoning with more salt and black pepper if needed.

Serve the savory oats in bowls. Top each serving with a soft egg, some grated Parmesan (if using), and thinly sliced scallions. Optionally, season with additional salt and black pepper to taste.