Prepare the onions: If using leeks or scallions, cut off the tough, white end, separate the green leaves, wash under running water, and pat dry. Cut lengthwise then snip with shears or chop into small pieces, then add to the large pot with olive oil. For other onions, peel and slice thinly, then add to pot. Set an onion timer for 10 minutes on medium heat and cook, stirring often, until translucent. Turn down the heat if they start to brown.
While onions are cooking: Zest all of the lemon and set zest aside. Then cut and juice the lemon. Set juice aside. Place colander in sink and drain all the beans, rinsing them well with cold running water, then leave the colander in the sink to drain.
Preheat the air fryer for the bread, 400F.
Make marinade. In the medium glass bowl, combine all lemon zest, 1 teaspoon paprika, 1 heaping teaspoon of minced garlic, ½ teaspoon salt and ½ teaspoon of pepper. Add shrimp and toss to coat. Shrimp will thaw as it sits in the marinade. Set aside.
Add bread to air fryer.
When the onion timer goes off, add the two tablespoons of butter to the pot with onions, stirring so it melts, bubbles and browns slightly.
Add shrimp and all marinade to the pot. The small shrimp will cook fast; use tongs to toss together the butter, onions and shrimp for about one minute.
To the shrimp and onions, add the broth, the drained beans, lemon juice, and parsley. Gently stir with wooden spoon. Taste and add salt as desired.
Heat through on medium high, about five minutes, watching carefully and stirring to ensure it doesn’t boil. Then turn off the heat—it’s time to eat!
Ladle into serving bowls, making sure each bowl gets plenty of beans and shrimp; garnish with thyme leaves as desired, and offer hot buttered bread on the side.