Cook pasta until barely tender; drain and set aside.
Melt margarine in a saucepan and add flour. Slowly add the soy milk, constantly whisking the mixture. If the consistency is not thick enough, slowly sprinkle in some flour, starting with ½ T and adding more if necessary. Meanwhile, continue whisking. Add cheese, garlic, onion, parsley, salt, and pepper. Whisk until sauce is thick and smooth.
Combine sauce and pasta, and sprinkle with paprika. Bake at 375 degrees in a greased casserole dish for at least 30 minutes. Or until the top is golden and crispy.
Recipe by Go Dairy Free at https://www.godairyfree.org/?p=161376