Rinse and dry salmon fillets. Season with salt and pepper. Heat 2 tablespoons oil in a large skillet over medium high heat. When pan is hot, add salmon skin side up. Sear for 4 to 5 minutes, flip, and sear 2 to 4 minutes or until salmon reaches internal temperature of 135°F.
Turn off heat, remove salmon from pan to a clean plate, and cover lightly with foil. Using paper towels, wipe pan clean.
For sauce:
Heat same skillet over medium heat; add olive oil and butter. When butter is melted, add poblanos, onions, and ¼ teaspoon salt. Sauté 10 minutes, or until softened.
Add garlic, sauté, stirring constantly, for 1 minute or until garlic is fragrant.
Add flour, stir and cook for one minute. Vegetables will be coated with flour.
Slowly whisk in milk, stirring constantly. Bring to a simmer; cook and stir for 1 minute, or until thickened.
Add spinach and cilantro, stirring constantly until spinach is wilted.
To serve, divide creamy spinach mixture onto 4 plates or shallow bowls, and nestle one salmon fillet in each serving. Serve immediately, garnished with a wedge of lemon.
Video
Notes
Substitute bell peppers or mushrooms for the poblanos, if desired.
Leftovers can be gently reheated in the microwave. Overheating may cause the salmon to become dry and the sauce may separate.