2 pork tenderloins (trimmed, about 2 pounds total)
1/4 cup fresh lemon juice (preferably Meyer)
1 tablespoon minced fresh garlic
1 tablespoon Dijon mustard
1 teaspoon dried thyme or 1 tablespoon fresh thyme leaves
1/2 teaspoon salt
1/4 cup extra-virgin olive oil
  Fresh thyme sprigs (as garnish, optional)