If I buy lobsters to eat at home, there's only one way I'm going to eat them: cooked whole and dipped in drawn butter. I will crack the shells at the table, I will chew on the legs, I will scoop out and eat the tomalley (damn anyone who says it's not healthy), and I will pick the body until not a shred of meat is left. What I'll almost never do is make lobster fra diavolo, the Italian-American pasta dish that features a spicy tomato sauce and lobster meat. Not because I don't like it, but because that dish is designed for restaurants.
Only in a restaurant does it make sense to collect enough lobster bodies—which most restaurant-goers have no interest in picking apart—to extract their flavor into a rich stock. That stock is flavorful enough that even when it's used as the base for a spicy tomato sauce, its essence-de-crustacean shines right through. And by capturing all that lobster flavor in the sauce and stretching it with spaghetti or linguine, the restaurant can also save money by using less than one lobster's worth of meat per serving.
While this can be done at home, it doesn't make a ton of sense. That's where shrimp fra diavolo comes in. Shrimp are less expensive and require less work to prep and shell, while still providing a similar shellfish experience. The problem, though, is in the sauce.
See, with most recipes for shrimp fra diavolo you sauté some shrimp, make a quick, spicy tomato sauce, and then toss the two together with pasta. This is definitely quick and easy, but it lacks one of the main appeals of lobster fra diavolo: that shellfish flavor permeating every last bite of sauce and pasta. So that's what my recipe sets out to fix, while still keeping the process easy and quick.
The main question that needs answering is how to get some shellfish flavor into the tomato sauce. We don't want to simmer the shrimp themselves in it for any length of time, because they'll rapidly overcook. Part of the answer lies in using their shells: not to make a stock, which would be too time consuming for what is ideally a quick-cooking dish, but to infuse their essence into the olive oil that we'll eventually use to make the sauce. Crustacean shells have a lot of flavor and color molecules that are fat soluble, so the technique works well.
I start by shelling the shrimp and searing the shells in olive oil until they've turned a reddish color. Using tongs and a slotted spatula I remove and discard the shells, leaving the oil behind. Next, I add the shrimp, which I've previously mixed with a small amount of baking soda and salt—a trick that helps them retain a firmer, snappy texture (more on that here). I cook the shrimp in the same oil over high heat so that they sear a little on the outside yet remain a hair underdone in the center, then I take them out and set them aside.
Next, I sauté some sliced garlic, dried oregano, and plenty of crushed *red pepper flakes, which will deliver the heat. Once the garlic is just starting to turn golden, I like to add a splash of brandy to the pan. This is not required, so feel free to skip it, but it's a flavor that works really well with shellfish (it's classic in a lobster stock, for instance). Please be careful adding hard liquor to the pan, as it's easy for the whole thing to go up in flames—not a problem if you're prepared to flambé but quite a surprise if you're not.
*It's almost impossible to give an accurate measurement in a recipe for red pepper flakes. I've found far too much variation in the heat intensity of red pepper flakes from one batch and brand to the next to be able to slap a quantified amount on it. You need to taste your red pepper flakes, get a sense of how hot they are, consider how spicy you like your food, and proceed from there. Some chili flakes can deliver enough heat with just a teaspoon's worth, others could require up to a tablespoon or two to deliver enough heat.
I add puréed whole peeled plum tomatoes next. I prefer to either purée them coarsely or crush them by hand, so that they maintain some texture. Why use whole canned tomatoes if we're just going to crush them anyway? Because they're often better quality tomatoes than the ones that end up in pureed and crushed products, and are more likely to not contain calcium chloride, a firming agent that can prevent the tomatoes from breaking down during cooking. You can read more canned tomato buying tips here.
As a last step, I whip out my secret ingredient: bottled clam juice. A little bit of this is the second half of my solution to getting shellfish flavor into the sauce. The key is to add just enough. We're not looking for a red clam sauce; we want a subtle hint of shellfish that infuses everything.
At this point, finishing the dish is just a matter of cooking the pasta, finishing it in the sauce, and adding the shrimp back in right at the end, just long enough to warm them through and finish any lingering cooking they have to do. A small handful of minced parsley adds a fresh green kick, as does a glug of some good olive oil.
The result is a shrimp-studded pasta infused with a shellfish flavor. You won't even miss the lobsters.