This classic dressing is tasty tossed with romaine, cucumber, red onion, and radish. Ours -- with paprika, canola oil, tomato paste, onion, lemon juice, and red wine vinegar -- is less sweet than many.
Whisk tomato paste, sugar, onion, mustard, paprikas, salt, and celery seed in a medium bowl; season with pepper. Whisk in vinegar and lemon juice. Add oil in a slow, steady stream, whisking until emulsified. Alternatively, puree all ingredients except the oil in a blender. With machine running, add oil in a slow, steady stream; blend until emulsified. Use dressing immediately.