These burgers look like regular burgers, but they have the surprise of a little nuggets of tarragon butter tucked into the center, which releases a burst of fresh herby flavor as you work your way through the burger.  You could use other fresh herbs in place of the tarragon, but I loved the way its anisey flavor played against the zip of the creamy, citrusy horseradish sauce.

Herb shears makes short work of mincing the tarragon leaves, and they are also kind of fun to use with three blades getting the job done in seconds.  There is also an integrated stem stripper, which helps you shimmy those leaves off the stem easily.

Tarragon Burgers:

2 tablespoons unsalted butter at room temperature

2 tablespoons minced fresh tarragon leaves

Kosher salt and freshly ground pepper to taste

1/2 teaspoon white wine vinegar

1 ½ pounds ground beef

4 hamburger buns

Horseradish Sauce:

1/2 cup sour cream
2 tablespoons jarred horseradish, drained

Finely grated zest and juice of 1 lime
Kosher salt and freshly ground pepper to taste

To Serve:

Sliced tomatoes, lettuce, sliced onions (optional)

In a small bowl mix together the butter, tarragon, vinegar, salt and pepper until well blended.  Place the butter on plastic wrap and using the plastic wrap, mold the butter into a short cylinder, about 2-inches long, and 1-inch in diameter.  Wrap up the butter in the plastic and place it in the freezer for 20 minutes until quite firm.

Meanwhile, make the horseradish sauce.  In a small bowl blend together the sour cream, horseradish, lime juice and zest, and salt and pepper.

When the butter is firm, preheat the grill to medium high.  To make the burgers, divide the meat into fourths, shape each fourth into a ball (be gentle when handling the beef; try not to press it too much).  Slice the butter into 4 even slices, each about ½-inch thick.  Use your thumb to make a depression in the middle of each ball.  Stuff a pat of the tarragon butter into the middle of each burger, and then gently but completely close the meat over the butter, as you form each burger into a 1-inch thick patty.  Use your fingers to press into the middle of each patty to create a small indentation, but don‘t allow the butter to peek through the meat.  This indentation will allow the burgers to stay flat as they cook, instead of puffing up in the middle.

Grill the burgers for about 5 minutes on each side, until done to your liking.  Towards the end of the burger cooking time, toast the buns on the grill for a minute if you like.  Transfer each burger to the bottom to a bun, and top with the horseradish sauce, and tomato, lettuce and onion as you wish.