In a pan over medium high heat, add the oil and allow it to get hot but not smoking.
Place the mushrooms in the pan. If the pan is too small for all of the mushrooms to fit, cook in two batches.
Turn the mushrooms once the bottom has turned dark and has softened, about 4 minutes.
Sprinkle with salt and allow to cook on the other side until the entire mushroom is dark, soft and cooked all the way through.
Remove cooked mushrooms from pan and add the spinach, onions and garlic, cook until soft.
Poach the eggs in lightly salted simmering water.
Melt the butter in the microwave.
In a good quality saucepan, add the yolks, lemon juice and water and whisk quickly and continually over low heat until it’s frothy and doubled in size.
While continuing to whisk, slowly add the butter in a steady stream.
Continue to whisk until thickened, and almost doubled.
If your sauce gets too dry and thick, you can add a few tbs of water.
Add the sriracha, and salt and pepper to taste.
Place the mushroom on a plate, top with spinach, then tomato slice, then poached egg and drizzle with hollandaise.
