Open Faced Portobello Sandwich

2 tbsp olive oil
2 cups Baby spinach
2 Portobello mushrooms (cleaned)
1 Avocado (pitted and sliced)
1 Lemon (juiced)
Sea salt and fresh ground pepper (to taste)
Preheat broiler to high heat. Brush the mushrooms with the olive oil and season with salt and pepper. Lay on a baking sheet and broil for 4 to 5 minutes, until lightly browned. Remove from oven and let cool slightly.
Top each mushroom half with spinach, and avocado. Drizzle with the lemon juice before serving.