A new full-service restaurant from Lettuce Entertain You, a pizza-and-pasta people-pleaser, instantly became the go-to riverside dining spot when it opened in July.

The Chicago River, a waterway historically known for ripe smells, unnatural holiday coloring and the engineering of its reversal, has seen another sort of reverse engineering over the past few years, as its downtown banks have developed into welcoming spaces for leisure.

A new full-service restaurant from Lettuce Entertain You Enterprises named Pizzeria Portofino, a pizza-and-pasta people-pleaser, instantly became the go-to riverside dining spot when it opened in July. It squeezes every drop out of its river adjacency, going deep into painting the river as the Riviera. Summery drinks, beachy umbrellas and loads of yachty blue stripes (on chairs, napkins, servers’ clothing) put the center of gravity on the 72-seat patio. You can dock your boat there.

But though summer is the theme, it’s perfectly appropriate (if loud inside) for a client lunch.

The menu lists grilled seafood and pastas, but its central pillar is pizza, in variants such as the angelic Burrata Diavola ($22) with one-per-slice burrata dollops and prosciutto under a mess of arugula, and the bitter-meets-meaty Pugliese ($18) with fennel sausage, rapini and chili flakes. In volume, each thin-crust pie feeds one; two if you’re having salad (four are listed; the Mediterranean, basically a Greek with a lot of herbs, was quite good).

Warm weather is waning. While Pizzeria Portofino will still have pizza inside the closed windows in winter, getting there promptly is the way to suck the marrow from summer.

THIN-SLICING PIZZA TAXONOMY

Servers describe the style of the pizzas as a very thin, crisp crust, a description similar to South Side tavern-style thin crust. Unlike typical tavern-style pies, however, the crown at Portofino is puffy and blistered, like Neapolitan pizzas. On one of our visits, the center of the pizza was also soft like Neapolitan, making a foldable slice.

EASY AS (PIZZA) PIE

As the first of three components in Lettuce’s dining options all in the same building, Pizzeria Portofino displays Lettuce’s signature tight conceptualization. Here, the concept is pleasant food in a pleasant setting, so the food situates itself as the opposite of scary. Even less-familiar dishes such as fried zucchini flowers ($13) stay safe, filled with melted cheese and served with a dipping sauce, like mozzarella sticks. The one exception, the profiteroles bianco dessert ($9), melanged together flavors of hazelnut, white chocolate, dark chocolate and salt, and successfully kept all those balls in the air.

OUTSIDE CHANCE

Reservations are hot, and probably will be whenever the weather is, too. You can declare a preference for patio seats when you reserve, but that won’t ensure you get them. So go early, before the patio fills, to up your chances of sitting by the water.