Heat your cast iron skillet over medium heat.
Season the chicken on both sides with salt and pepper.
4 boneless, skinless chicken breasts, 2 teaspoons kosher salt, 2 teaspoons black pepper
Cook the chicken in the cast iron skillet. First, add the olive oil, then cook the chicken about 8 minutes per side, until golden brown and the internal temperature reaches 165º degrees. Transfer the cooked chicken to a plate.
1 tablespoon olive oil
Brown the onions and garlic. In the same skillet, add the choped onions and season with a pinch salt and pepper. Cook for about 4 minutes, scraping up any brown bits at the bottom of the pan while they're cooking for maximum flavor. Add the garlic cloves, and cook just 30 seconds.
1 yellow onion, 2 cloves garlic
Make the sauce. Add the white wine, dijon mustard, and stir to combine. Cook until the sauce has reduced by half, will take about 5 minutes. Turn the heat to low, then add the heavy cream and butter. Whisk to combine. Add the chicken back to the skillet to warm thru.
3 cups white wine, 1/4 cup dijon mustard, 1 tablespoon butter, 2 tablespoons heavy whipping cream
Serve the chicken warm, topped with the creamy dijon mustard sauce and chopped chives. I love this on top of white rice, cauliflower rice, mashed potatoes, mashed cauliflower or roasted potatoes. See the Recipe Notes below for more tips, FAQ's and ingredient substitutions.