After a dearth of responses (thanks Jen Kalb for chiming in), I'm reporting back on our eating adventures around Bagni di Lucca. I should state up front that we didn't eat any meals in Bagni di Lucca proper, though we did partake of the thermal baths, which was a very strange and old world experience that made us feel connected to all the 19th century travelers who took the waters in this once-thriving resort town.
Our first meal in the region was lunch in the tiny town of San Cassiano, about a 20 minute drive up into the mountains. The sign outside says "Bar Trattoria Pizzeria da Santina" and walking in it looks like a diner or dive bar, but there's a terrace in the back with a magnificent view of the mountains. There's no menu here--they just bring you whatever they're cooking. The meal started with plates of prosciutto and finocchiona, followed by slices of zucchini fried in a light, crispy batter. Next was a pasta so eggy it was yellow. One pasta had a meat ragu and the other a mushroom sauce. The secondi consisted of very thinly sliced veal in a salsa verde. Unlimited carafes of white wine kept coming out. The price was 20 euros per person. A bonus is the 8th century church in this little town.
We had lunch the next day at Ristorante al Laghetto. This place is listed as being in the town of Fabbriche di Vergemoli, but it was a rural location with the added bonus of being able to wade in the Lago di Turrite Cava across the road afterwards. There was a rather worse for the wear taxidermied boar outside, which was not indicative of the food we had. Again, no menu. The meal started with some of the best tomato bruschetta we had in Italy. The bread was rustic and toothy, with very fresh garlic and perfect tomatoes. Primi was a lasagna, a ravioli dish, and a farro / bean soup. The ravioli was basically just large sheets of pasta with a ricotta / pesto filling and mozzarella on top. The lasagna filling tasted almost like mascarpone. For secondi, we had a mixed grill--chicken, beef ribs, and rabbit. The rabbit was butchered so that the kidneys, etc. were attached to the cuts. All perfectly grilled. This place is famous locally for an espresso / sambuca drink called a bomba, which is delivered on fire with its own theme song cranked up for the time it takes to bring it, flaming, to the table.
A guided tour of Lucca was followed by lunch at all'Olivo, which was perfectly good but not especially memorable.
We had dinner that night at the Michelin-starred Antica Locanda di Sesto a ways outside the walls of Lucca, which claims to have originated in the 14th century. It was indeed a very beautiful, old space. We were met with a glass of Prosecco and more delicious tomato bruschetta. For the antipasti we had lardo draped over a sprig of rosemary and a very generous selection of local pecorinos served with honey and jam. For the primi, I had a pasta with mozzarella and fresh tomatoes and my spouse had their version of carbonara--bucatini with guanciale that was brought to the table in a skillet and dumped into a carved out round of Parmesan, where it was tossed for a good minute before being placed in a bowl and served. Though we were already stuffed, my spouse had the osso buco and I had pork chops pounded thin, breaded and fried, and covered with yet more fresh tomatoes. With a bottle of wine, the entire meal came to under 125 euros, which seemed astonishing for the quality and quantity of food.
One day we drove to Vecchio Mulino in Castelnuovo, which was the one recommendation we got from the Chowhound community for this area. Yet again, no menu, but we simply asked for an assortment of what they were serving, which was more about small bites--salads, crostini, cured meats, cheeses, and torta. It was a lovely sampling of lovingly prepared foods, and the largest mortadella any of us had ever seen.
We had lunch one day at Osteria i Macelli in Borgo. We didn't see a lot of green salads while we were in Italy, but this place had a gorgeous salad with quail eggs. We had stuffed zucchini flowers, followed by a lemon pasta. The place was empty on a Friday afternoon.
Finally, we had two dinners at Il Biribisso (it was the closest restaurant to our vacation rental). Though you can get other things there, their specialty is steak. The antipasti was forgettable, though the nettle ravioli was a big hit. The four of us dining that night ordered the grilled steak. They brought out a 2.5 kg piece of raw bone-in beef to show us before cooking it "bleu." It was truly almost entirely raw, but it was delicious. You could choose from a variety of toppings. We had lardo and rosemary. Our second dinner there we tried the pizza, their other specialty. There was an unusual pizza with borlotti beans, not entirely successful, but the pizza was fine. Probably more impressive to visitors who don't have access to the obsessive pizza culture of New York City.