Chorizo Burgers

Ingredients (12)

• 1/3 cup sugar
• 1/3 cup water
• 1/3 cup cider vinegar
• 1/2 large red onion, halved and thinly sliced
• 1 jalapeno pepper, sliced
• 6 ounces ground beef or bison
• 1/4 pound fresh chorizo or bulk spicy pork sausage
• 1/4 teaspoon salt
• 1/4 teaspoon pepper
• 2 sesame seed hamburger buns, split
• 1/2 cup fresh baby spinach
• 2 tablespoons peeled and grated horseradish