Both Mr. DeSpoon and I were nodding, our mouths full and eyes big with approval. “I could eat a dozen of these,” he said, though I found that hard to imagine. These are ample turnovers. You wouldn’t go wrong ordering two or three and making a lunch of it.

Next out was the Green Banana Croquette ($2.25). Plantains are an island staple and appear throughout the menu. Not at all sweet, the croquette was good though even Mr. DeSpoon found it a bit bland compared to the empanadilla. 

Our third appetizer was a Stuffed Potato Ball ($2), about the size of a tennis ball. This Puerto Rican version of a twice-baked potato has a ground-meat center surrounded by mashed potato toasted to a crispy crust. We agreed: the potato ball was both delicious and amusing.
Thirsty, I checked the beverage menu.  In parentheses beside a drink called Guanaba was “soursop,” which struck me as the perfect word to describe the smell when you forget to take clothes out of the washer. Curiosity demanded I try it. Of course, more worldly diners know that soursop is a tropical fruit popular in Puerto Rico. Guanaba ($2) over ice is fantastic. The flavor of the soursop is part pineapple, part strawberry, part I-don’t-know-what. It’s my new favorite drink.

Lunch and dinner choices are similar, as are the prices. I chose El Convento ($7.50), a traditional plate of pork shoulder with rice and pigeon peas served with a salad. It was well-prepared and enjoyable, though not distinctive.

Mr. DeSpoon, after much discussion with the restaurant’s owner, decided on their signature dish: the Mofongo Relleno ($10.95). Described as a stuffed plantain ball, it would look, we assumed, like a grapefruit-sized version of the potato ball. 

We underestimated the Mofongo.

Mr. DeSpoon’s Mofongo Relleno (the pork-stuffed version includes salad) arrived mounding out of a wooden vessel that was a cross between a goblet and a candleholder, a presentation that deserved its own soundtrack. It was accompanied by a simple bowl of chicken broth.
 
We learned, thanks to our hosts, to make a hollow in the top of the Mofongo and spoon the broth in. The outer layer was like the most delicious Thanksgiving dressing you can imagine, mashed plantains with crispy bits of pork. In the center, we found juicy roast pork. The owner told us this dish had kept him in business. We could see why.

We knew Puerto Rican cuisine was not Mexican food, but beyond that, we knew little. If like us, you’re expecting food with some spice, you should know that nothing we tasted packed any heat.

Our food was full of flavor, though, and portions were generous. Like others before us, we will return for the Mofongo — and the empanadillas, which Mr. DeSpoon would “put up against a taco anytime.” Of course, escaping to tropical Puerto Rico and plucking fruit fresh from the soursop tree sounds ideal. But the family run Old San Juan Restaurant offers a satisfying alternative.