Opaque Restaurant is a 'dining in the dark' restaurant that features chef Mike Whang. (Opaque/OPAQUE)

The unidentifiable object tasted oh-so familiar. I chewed slowly and deliberately, squinting my eyes to help zero in on the flavor. Then, totally exasperated, I shook my head and flopped back in my seat. But I was sitting in a pitch-black dining room, and nobody could see the body language of my torment. So I sighed. Loudly.

“I don’t even know if it’s a fruit or a vegetable or meat,” I said to my blind friend, Travis. “It could be anything.”

Travis and I were sitting in San Francisco’s Opaque restaurant, a dining-in-the-dark concept modeled after similar eateries in Europe. The servers are blind or vision-impaired, and the patrons, who are mostly sighted, dine there for the novelty of eating without seeing.

Travis lost all his vision after being injured while serving in Iraq, and, especially at first, he wanted friends to appreciate how hard it was for him to eat. Going on a “blind date” during my West Coast visit seemed like a good way to experience the world through Travis’s eyes, so to speak. So I prepared myself to surrender my most reliable sense. What I didn’t expect was the biggest seated adventure of my life.

Opaque is on an unassuming block in the city’s Hayes Valley neighborhood, in the basement of another restaurant. At the top of the stairs, we checked in with the hostess, and she handed us prix-fixe menus. Travis, his guide dog, Fess, and I walked downstairs, sat on a bench and selected our appetizers, entrees and desserts.

Our server, Courtney, arrived and we made a train — hands on shoulders — to follow her into the black. She steered us around poles and door jambs and into our U-shaped booth. I asked her about the extent of her vision. “It deteriorates over time,” she told us. “I describe it as looking through a shower door — the frosted kind — and it’s pretty damn frosted at this point.” She told us to call out if we needed anything.

Travis and I felt around our booth. We decided that the back cushion might have been a retired gym mat. The white tablecloth I imagined could have been purple. Even Fess seemed disoriented: When Travis leaned over to give him a treat, it took him longer to find it, having to depend on his sniffer.

“We ready to get started?” I heard Courtney’s voice on my right. “The way it’s going to work is, when I hand you something or you hand me something, our hands will meet on the corner of the table,” she said. “So now I’m going to hand you each a glass of ice water. Go ahead and place it wherever is convenient for you.”

Then she handed us second glasses and an amuse-bouche — a cucumber slice with smoked salmon and wasabi aioli, compliments of the fully sighted chef. Then came the bread basket and the butter ramekin, which I held in my lap so I wouldn’t lose it. By the time Courtney was finished delivering and describing all these items, I felt completely lost, and my short-term memory had failed me: I had to ask her to repeat what was on the amuse-bouche plate. Half-listening, I realized, wouldn’t get me very far at Opaque.

Travis offered some helpful tips, such as running my fingers along the table edge to find things. “You start reaching across the table, that’s when you start knocking drinks over,” he said. I bravely buttered a slice of bread, only to learn that I’d left two giant chunks on the edges. Travis said that if I paid attention to the friction and resistance of the knife, I could tell how much I was spreading. All good advice, but I was less concerned with physics than my now butter-covered fingers.

Courtney brought our starters — a baby green salad for me and ahi tuna for Travis. The first thing I stabbed was the chunky piece that would drive me mad with its mystery. I took one bite and held the rest of it in my left hand for about 10 minutes, hoping that intermittent bites between baby greens would trigger my memory.

“I’m telling you, all your senses are so handicapped by your sight,” Travis said. “Even your taste.”

At last, in a thrilling moment, it came to me: “It’s a mushroom! A portobello mushroom!”

The rest of the meal was less frustrating, and I found myself closing my eyes for long periods of time. There was a lot of touching of food that wasn’t finger food and plenty of laughing every time the fork arrived at my mouth. Either it was empty or the piece I’d cut was so big it hit my nose. I remember enjoying the food, but the flavors were somewhat lost to the celebration of each triumphant self-feeding.

After dessert (bittersweet chocolate cake with strawberries and vanilla bean ice cream), Courtney led us back to the light. It was dusk, but I squinted going up the stairs. After 21 / 2 hours without my sight, readjusting my eyes threw off my equilibrium, and I felt faintly dizzy and queasy.

We paid the hostess, and I picked up a brochure on our way out. “Not just a meal,” it read, “but a truly unique, sensual experience.” I didn’t know about sensual, but I was certain I still had some aioli on my cheek and chocolate on my fingers as I grabbed the steering wheel of my rental. Travis and Fess sat on the passenger side, eyes wide open.

Kaplan is a freelance writer in Washington. She can be found at www.melaniedgkaplan.com.