Wonderful but acquired taste.
Combine beans, onions, salad oil, vinegar, salt & pepper in a bowl; toss lightly. Cover and chill for several hours
Mix boiled eggs, mayonnaise, mustard, vinegar and salt. Cover and chill.
To serve, drain bean mixture and mix with bacon. Serve on crisp lettuce; beans and then a scoop of eggs. Sprinkle with paprika.