Begin by finely chopping the yellow onion and mincing the garlic cloves. Pat the skinless salmon fillets dry with a paper towel, then season generously with salt and black pepper.

In a large nonstick skillet, heat 1 tablespoon of olive oil along with 1 tablespoon of unsalted butter over medium heat. Once the butter is melted and bubbling, carefully add the seasoned salmon fillets. Sear them for about 3–4 minutes on each side until they are golden brown.

Reduce the skillet heat to low and add the chopped onion and minced garlic. Sauté for about 2 minutes until the onion is translucent and softened.

To the softened onions and garlic, stir in one anchovy fillet, fresh chili or red chili flakes for heat, along with dried oregano, sage, sweet paprika, and a pinch of salt and black pepper. Cook for 1 minute.

Add 2 tablespoons of tomato paste and 1 cup of chicken broth to the skillet, stirring well. Allow the sauce to simmer for about 2 minutes.

Pour in a can of crushed tomatoes, stirring thoroughly. Bring the sauce to a gentle simmer, letting it thicken for about 5 minutes.

Once the sauce has thickened, stir in about 2 cups of fresh spinach. Cook for about 2 minutes until the spinach is slightly wilted.

Return the seared salmon fillets to the skillet, gently nestling them into the sauce. Cook for an additional 3 minutes.

Remove the skillet from heat and plate the Salmon all’Arrabbiata. Top each portion with an extra sprinkle of red pepper flakes, freshly ground black pepper, and chopped parsley.