This escabeche is very light and tart, and as with everything in my cooking, not loaded with lot of oil. It was created for the restaurant Carmen at The Danforth in Portland, Maine, where we had so much fresh fish and great sardines. I like that this is a very variable recipe. If you have company, for example, you can make the marinade ahead of time and keep it, and then bring to room temperature quickly and drizzle it on top of your sardines. Or you can let the fish marinating for a long time, like they do in Spain and Puerto Rico.
Heat the olive oil in a 10-inch sauté pan over medium-high heat. Add the garlic and bay leaves and cook until the garlic just begins to turn golden brown, 1 1/2 to 2 minutes. While stirring, add the paprika and thyme, then slowly add the vinegar and bring to a boil. Reduce the heat to medium, add the salt, and simmer for 5 to 7 minutes. Set aside to let cool until lukewarm. (The marinade can be refrigerated, tightly covered, for up to 1 day.)
To fillet the sardines, cut halfway through at the point between the head and body, then turn the knife 90 degrees.
Steady the fish with your other hand and, using the bones as a guide, slowly press the knife lightly and follow all the way through to the tail.
Use your fingers to turn the fillet from the body (like opening a book) andbegin cutting down the spine, working the knife just above the bone, until you remove the fillet from the body. Repeat on the other side. (Or better yet, ask your fish monger to fillet the sardines for you.)
If the marinade was refrigerated, reheat it over very low heat until warm.
Spread the flour out on a plate. One at a time, dredge 3 or 4 sardine fillets lightly in the flour, and shake off excess flour.
Heat about 1/8 inch of olive oil in a large skillet over medium-high heat. Add the sardines, skin side down, to the hot oil. Fry, turning once with a spatula or tongs, until crisp and golden, for 1 to 2 minutes per side. Remove from the pan and drain on paper towels.
Repeat with the remaining sardines, adding more oil if necessary between batches.
Transfer the sardines to a serving plate and pour the marinade over them. You can serve the sardines right away, or let them marinate for up to 2 hours at room temperature to get a more pickled flavor.