Begin by heating 2 teaspoons of olive oil in a medium skillet over medium heat. Once the oil shimmers, add the sliced onion along with a pinch of salt. Sauté for about 3-4 minutes until the onions become translucent and fragrant.

Next, stir in 1-2 minced garlic cloves and cook for an additional 1-2 minutes, avoiding browning.

Add the sliced portobello and Swiss brown mushrooms to the skillet, drizzling them lightly with another teaspoon of olive oil. Increase the heat to high and sauté for about 5-7 minutes, seasoning with salt, pepper, and chopped parsley.

In a mixing bowl, combine a handful of arugula with a drizzle of olive oil, 1 teaspoon of balsamic vinegar, and a pinch of salt. Toss gently until lightly coated.

To finish, spread a generous layer of creamy ricotta cheese onto your toasted slices of whole grain sourdough. Layer the sautéed mushrooms evenly over the ricotta, followed by the arugula salad. Serve warm, sprinkling with optional chili flakes if desired.