The French have a phrase, “l’appel du vide,” or “call of the void.” It’s the sudden urge to do something insanely dangerous on a whim, like when you’re looking down from a high place and contemplate jumping. I was thinking about that expression the other day while having lunch at the nonprofit pay-what-you-can eatery Taste Community Kitchen (1200 S Main St, 817-759-9045), which opened back in December. My lunch guest could not wrap his head around the idea that the menu didn’t have prices.

“We could, theoretically, just leave one dollar on the table and walk out of here,” he kind of suggested.

Yeah, you could do that. You could also dart into traffic with your shirt pulled over your head or hurl yourself off a bridge trying to land in the back of a passing pick-up truck. We resist the call of the void because such behavior is not only outlandishly stupid, but it would also impact a lot of people – which brings me to Taste.

For those who are unfamiliar with Taste’s story/ethos, the hip-looking Near Southside lunch spot is staffed with mostly volunteers and serves its great food to people all over the socioeconomic spectrum. Here are some simple rules: If you have enough money to afford a name-brand watch, you have an ethical obligation to overpay. You’re subsidizing the rest of us. If you’ve never owned a watch, then just pay what you can (or don’t pay) and enjoy your lunch. For those of us in the middle of the timepiece continuum, knowing how much to shell out can trigger a specific kind of anxiety. (I’m sure the Germans have a word for it. They have the word kummerspeck, which literally translates to “grief bacon.” Like, when you eat your feelings. That’s unrelated to this column, but Germans have sooo many cool words.)

How do you know what is fair value at a pay-what-you-can place? Every restaurant’s price point is dependent on so many factors: Rent, the quality of the ingredients, and, hell, even gas prices can impact how much coin you drop.

I’ve invented what I call the Proximity Value Standard (PVS) but only because I’ve given up trying to create a funny acronym. (I also came up with GAS –– Geographical Assessment Standard –– but that wasn’t very precise.) All you have to do is find or recall a nearby restaurant that serves similar-looking food and use its prices. With PVS, things like rent, distributors’ cost, and labor are probably similar and already factored into the prices. You have to do some adjusting based on a wide-range of (mostly arbitrary) factors, but PVS gets you in the ballpark.

On my recent visit to Taste, I started with a refreshing watermelon gazpacho – finely chopped veggies and sprigs of mint swimming in a sweet, cold broth. I recently had a gazpacho at Magnolia Avenue standout Ellerbe Fine Foods, and that cost $8. Taking into consideration the low cost of watermelon and the insanely high quality of ingredients used by Chef Molly McCook’s kitchen, I comfortably chopped $2 off my Taste total, so my PVS for the soup was $6.

I’ve never seen anything similar to my guest’s creamy, crunchy elote fritters around that part of town, but they sound like the sort of thing that Brewed might put out. All of their apps fall in the $6-12 range, and I figured fried corn would be on the low end of that spectrum, so the adjusted PVS was $6.

For my pork ribs entree, slathered in a stone-fruit barbecue sauce and topped with haystack onions and accompanied by mac ’n’ cheese, I took Heim Barbecue and Catering’s price for ribs ($18) and cut it in half (because Heim). Every chicken entree on the lunch menu at Lili’s Bistro hovers around $12, so adjusting for the gratuitous use of gorgonzola by Lili’s chef Vance Martin, I figured my guest’s green chile chicken, topped with a garlicky chimichurri, would run about $10.

So that’s $31 total. And since the waitstaff doesn’t take tips, I added on a few bucks, bringing our total bill to $37. I had a great meal, donated to charity, and taught my guest a little French. Talk about a productive lunch!