- 2 pounds ground beef, grass-fed if available
- 2-2 1/2 cups roasted vegetables (see note)
- 3 eggs, lightly beaten
- kosher salt and freshly ground pepper
- 1 teaspoon dried thyme or 1 tablespoon fresh
- 1/4 cup chopped fresh parsley
- 1/2-1 cup panko (or oats)
- 1/2 cup freshly-grated Parmesan
- 1/2 +1/3 cup ketchup, divided
- 3-4 tablespoons balsamic vinegar, divided