Servings: 2 servings.
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, seeded and 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
