Preheat a grill pan and preheat a sandwich press, or heat a large cast-iron skillet over medium-high heat. Brush asparagus with oil, and place on grill pan. Cook, turning occasionally, until cooked through and charred all over, about 10 minutes; set aside.
Spread bottom slice of focaccia with sundried tomatoes. Top with tofu, spinach, and asparagus. Cover with top slice of focaccia.
Place sandwich into press. Close press, and cook until bread is lightly toasted, about 5 minutes. Alternately, place sandwich in heated skillet, and weight with a heavy pan lid; cook until golden brown on both sides, turning once after about 4 minutes.