- 4 Italian sausages (about 1 pound)
- 8 plum tomatoes, cut in half crosswise
- 1 onion, sliced into 1/2-inch-thick rings
- 4 tablespoons extra-virgin olive oil
- kosher salt and pepper
- 3 bunches spinach, thick stems removed (about 8 cups)
- 1 tablespoon balsamic vinegar
- 1 tablespoon whole-grain mustard
- Heat grill to medium-high. With a fork, prick the sausages in several places. Grill, turning occasionally, until cooked through, 10 to 12 minutes.
- Meanwhile, brush the tomatoes and onion with 1 tablespoon of the oil and season with ½ teaspoon salt and ¼ teaspoon pepper.
- Grill vegetables until tender, 5 to 6 minutes per side for the onion and 2 to 3 minutes per side for the tomatoes. Transfer to a bowl as they are done.
- Add the spinach to the bowl and toss.
- In a small bowl, whisk together the vinegar, mustard, remaining 3 tablespoons oil, ½ teaspoon salt, and ¼ teaspoon pepper.
- Slice the sausages and serve with the vegetables and dressing.