Preheat oven to 200°C (390ºF). Place the sweet potato and tomato, cut-side up, in a baking dish. Drizzle with oil and bake for 35–45 minutes or until the sweet potato is soft and golden.
Cook the pasta in a large saucepan of salted boiling water until al dente. Drain and combine with the sweet potato, tomato, spinach, parmesan, salt and pepper. Place in serving bowls, top with the feta and drizzle with lemon juice and oil to serve. Serves 4.