Start by making shallow diagonal cuts on the salmon fillet, then make cuts in the opposite diagonal.
Fill a large skillet over medium to low heat with vegetable oil and let it heat up.
Add the salmon fillet and fry until lightly golden brown, spooning oil over it.
Remove it from the skillet, cut it into strips and set it aside.
In a large skillet over medium to low heat, add a drizzle of olive oil.
Add the onion sliced into strips, the red bell pepper also sliced into strips and sauté everything until softened.
Next, add the mushrooms chopped into smaller pieces and the spinach leaves.
Season with the salt, the black pepper, the garlic powder and sauté for another 2 minutes.
Add the heavy cream, the water and stir to combine.
Now, add the salmon, season with a pinch of salt and a pinch of black pepper.
Add the lemon sliced into rounds, cover the skillet and let everything cook for 10 minutes.
Serve.