Break pasta in half and prepare per package instructions, about 7 minutes. Bring a large skillet sprayed with nonstick spray to medium-high heat on the stove. Add soy crumbles, crushed tomatoes, and taco seasoning, and mix well. Cook and stir until hot, 2 to 4 minutes. Drain the pasta and add it to the skillet. Mix well. Evenly distribute the pasta among the taco shells, about 1/3 cup per shell. Top each evenly with cheese, onion, and lettuce. Tada!