Season all sides of salmon fillets with salt and pepper. Place flour in shallow dish and dredge all sides of each piece of salmon with flour, shaking off excess flour.

In large nonstick skillet, melt 1 tablespoon butter over medium-high heat. Add olive oil and swirl to mix butter and olive oil.

Add salmon to skillet and cook 6 to 8 minutes or until salmon is deep golden brown and easily releases from pan, turning once halfway through cooking, and gently pressing each side of the salmon down with a spatula so it makes good contact with the pan. Transfer salmon to a plate and cover with foil to keep warm. 

Reduce heat on skillet to medium-low. Add garlic and cook 15 seconds or until garlic is fragrant. 

Add broth, wine and lemon juice to skillet and increase heat to medium-high. Cook 8 to 10 minutes or until mixture is reduced by half, stirring and scraping bottom of pan as it cooks.

Reduce heat to medium-low and stir in capers, thyme, lemon zest and remaining 2 tablespoons butter. Taste sauce and season with additional salt and pepper if desired. When butter is melted, transfer salmon back to skillet and turn so salmon is covered in sauce. Garnish with parsley and lemon slices, if desired, and serve immediately.