Remove the salmon fillets from the refrigerator and let them sit for 15–30 minutes to come to room temperature. Cut the salmon into four equal pieces, then pat them dry with paper towels. Season both sides generously with garlic powder, salt, and pepper.

Heat a large skillet over medium-high heat, adding a blend of olive oil and butter. Once the butter is melted and bubbling, carefully place the salmon in the skillet. Sear for 3–4 minutes until the bottom is golden brown, then flip and cook for another 3–4 minutes.

In the same skillet, reduce the heat to medium and add the chopped onions. Sauté for about 5 minutes, stirring occasionally, until softened and golden brown.

Pour in the chicken broth and lemon juice, stirring to combine with the onions. Add the softened Boursin cheese, mixing until the sauce is smooth and fully combined. Allow the mixture to bubble gently for about 4–5 minutes.

Carefully return the seared salmon to the skillet, spooning some sauce over each piece. Reduce the heat to low and cover, simmering for 3–5 minutes until the salmon is flaky and cooked through.

Remove from heat and garnish with chopped parsley. Serve immediately.