This classic salad 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.