Preheat your oven to 400°F and line a small baking sheet with parchment paper.
Clean the portobello mushrooms with a damp cloth, remove the stems, and gently scrape out the dark gills with a spoon.
In a medium skillet over medium-high heat, add the olive oil and ground turkey, breaking it up with a spatula as it browns.
Once the turkey is nearly cooked through, add the minced garlic, chopped spinach, sea salt, and black pepper, sautéing until the spinach is wilted.
Stir in the fresh chopped parsley and remove the skillet from the heat.
Place the mushroom caps on the baking sheet, gill-side up, and divide the turkey mixture evenly between the two caps.
Roast in the oven for 15 to 18 minutes until the mushrooms are tender and juicy.
Remove from the oven and drizzle the balsamic glaze over the top before serving.