Even though my paternal grandfather was from Grumo Appula, a small town outside Bari in the southeastern Italian region of Puglia, I don't remember eating much pugliese food growing up. Other than a few dishes—orcecchiette with cime di rape (also known as broccoletti), that wonderful calzone di cipolla (onion pie) that I just recently rediscovered, and cavatieddi with tomato and ricotta—the Italian food I remember growing up with was basically from Angelina's native Campania. But I've always been curious about the cooking of Grandpa's native region.
When you mention pugliese cooking to many Italians, right after orecchiette they will often think of tiella pugliese, a hearty casserole of mussels with rice and potatoes, something like a cross between paella and a potato gratin. Although it requires a few preparatory steps and then a layering of different ingredients, it is a remarkably easy dish to make—after it is assembled it almost literally cooks itself. It makes a very satisfying piatto unico for a light dinner or first course of a substantial meal.
You begin by laying down thinly sliced onion, dressed with olive oil, on the bottom of a casserole dish. Over the onions lay slices of waxy potatoes, chopped parsley and garlic, and diced tomato, season generously with salt and pepper, sprinkle over grated pecorino cheese and drizzle with olive oil:
Next place down a layer of mussels on the half shell (see Notes below), season again and drizzle a bit of olive oil over each bit of mussel:
Then cover with Arborio rice, topping the rice with some more chopped garlic and parsley, chopped tomato, grated pecorino, season again and drizzle over some more olive oil:
Place a final layer of potatoes (which you may wish to arrange in a neat pattern for presentation at the table) then, if you like, season as you have the other layers. (Some recipes call for leaving this layer plain, for a neater presentation.) Pour in the juices of the mussels and enough simmering water (or, for more flavor, dish stock or clam juice) to just cover the potatoes.
Bring the casserole to a simmer on top of the stove and then place in a medium oven (180C, 350F) for 45 minutes to an hour, until the top is nicely brown, the rice is done and all the water absorbed but the casserole is still moist.
NOTES: To make a tiella, you traditionally use mussels 'on the half shell'. Before adding to the casserole, the mussels need to be opened, either by shucking them raw (which I personally find rather tricky) or by very briefly steaming them with a bit of water in a covered pot, and then removing the half of the shell that is not attached to the mussel meat. Although not traditional, for the sake of convenience, you can also simply buy shucked mussels and use them, without their shells. As always, smaller mussels will provide sweeter flavor and finer texture than larger ones. Wild mussels need to be soaked and trimmed but most mussels these days are raised in 'farms' and come ready to use (see this post for background).
The potatoes should, as mentioned, be of yellow-fleshed 'waxy' variety. In the US, red bliss would be a good choice, as would an all-purpose potato like Yukon Golds. Avoid mealy 'baking' potatoes like Russets, which will tend to fall apart as they cook.
The main 'tricks' to a good tiella, other than using the best quality ingredients you can find, are to season the dish adequately—more than you may think you need—and to make sure that the rice is done to the right point, neither chalky nor mushy. You can test the rice for doneness by gently opening the top layer of potatoes and trying a few grains. Add a bit more water (or clam juice) if you find the rice is not yet ready, or if the tiella is drying out too much—and continue cooking. (To avoid undercooked rice, some recipes call for soaking the rice before using, but I would think that this would soften the rice too much and ruin its texture.)
Like most traditional dishes, there are numerous variations. Some recipes call for making the dish in rosso—using not just bits of chopped tomato as pictured here but lots of tomato in layers. In contrast, some recipes call for a few cherry tomatoes, sliced in half, rather chopped tomato. Some recipes call for placing the mussels on the top of the rice, rather than vice versa. Some recipes call for various layers of onion, alternating with the other layers of potato, instead of just one layer at the bottom of the casserole; some recipes even eschew the garlic completely in favor of generous amounts of onion. And—for a summer variation—some recipes call for sliced zucchini interspersed with the potato. Some recipes call for breadcrumbs on top and/or interspersed with the other ingredients. And some recipes call for a mixture of grated parmesan and pecorino rather than all pecorino. All of these variations (with the possible exception of the last) sound good to me. If you would like a vegetarian tiella, just omit the seafood.
The name 'tiella' by the way, like 'paella' in Spanish and 'casserole' in English, refers both to the cooking vessel and the dish you cook in it. The tiella is typically made of terracotta. If you have a terracotta casserole, but all means use it—it somehow gives the food a special flavor that no other material can mimic—but otherwise enameled case iron or ceramic casserole will work just fine.
The name 'tiella' by the way, like 'paella' in Spanish and 'casserole' in English, refers both to the cooking vessel and the dish you cook in it. The tiella is typically made of terracotta. If you have a terracotta casserole, but all means use it—it somehow gives the food a special flavor that no other material can mimic—but otherwise enameled case iron or ceramic casserole will work just fine.
