The gratin can be made vegan, as we did that day, or with added proteins. I have been enjoying it with cheese curds and chopped bits of browned meat. Marshall recommends mushrooms as a meaty alternative. 
 
Two servings
 
2 cups carrots, cut into inch rounds 
2 cups potatoes, cut into inch chunks
2 cups cauliflower, separated into florets about an inch across 
1 teaspoon salt 
2 teaspoons pepper
3 tablespoons olive oil
2 cups bread crumbs
½ cup Biga Verde (recipe follows)
Optional: proteins, like cheese, meat or mushrooms
 
Soak the cut potatoes for 30 minutes in water, and drain. Toss the carrots and potatoes in olive oil, salt and pepper, and spread out evenly on the pan, filling all space. Bake at 450 until everything is golden, soft and puffy. Don't stir. 
 
When the roots are still warm but cool enough to work with, toss them with the crumbs, and then lightly toss in the verde and optional proteins, but don’t totally mix it up. There should be patches of unmixed, non-green roots. Spoon into ramekins and bake until the top develops a crust. 

The International Flavor of Green 
 
"He is the whole taco package. Verde sauce and everything, cilantro included. Whole ass man and I don't even deserve him."
 
I can't guarantee that every bite of verde will be as exciting as new love, as it was there on a social medium. But verde, like love, can be very good, and the above declaration says as much about the taco sauce as it does the taco. 
 
It goes without saying that the literal verde sauce to which the gentleman is compared is the Taco Bell variety, packages of which began disappearing about three years ago, when it was discontinued in order to make way for Diablo Sauce. Despite the protests, petitions, and all forms of unrest, the Taco Bell Verde Sauce has not returned. 
 
Verde, which means "green" in the Latin-based languages, appears nearly everywhere they are spoken, made from whatever ingredients are available, providing they are also tasty and green. In keeping it green we are limited to ingredients that contain chlorophyll, which isn't much of a limitation at all. Taco Bell Tomatillo is one of many shades and flavors of green. 

 
Like the Latin root, viridi, verde first appeared in the Mediterranean. In Spain, France and Italy the sauce was made with parsley, and that practice made it across the pond to the south of South America, where the parsley-based version known as chimichurri incorporated a New World plant known as the chile pepper. 
 
In the American Southwest, you can distinguish Mexican vs. New Mexican restaurants by the little bowl of verde sauce that comes with the obligatory basket of corn chips. Mexican verde hits you with the sour acid of tomatillo, while New Mexican green, as the locals call it, packs the fiery musk of roasted green chile. Both chile and tomatillos are nightshades, the New World family of plants that also includes tomatoes, potatoes and eggplant. 
 
The herb-based Old Country verde and the nightshade-based American verde converge daily at a pizzeria called Biga in Missoula, Montana, whose Meatball Verde pizza is topped with chopped broccoli rabe, beef meatball and mascarpone cheese, and drenched in a cilantro jalapeno verde. With both herbs and peppers, this sauce isa blend of old and new world concepts.
 
Biga Pizza's owner and chef Bob Marshall doesn't admit to intentionally tapping into any of this history. "I just wanted to make a taco pizza," he told me. 
 
Marshall chops the mild, tender leaves and stems, and lets them cook on the pie. "The bitter and astringent qualities balance the richness of the mascarpone and beef," he says. The way the rabe cooks down so perfectly in the oven, he adds, contributes to how the whole thing holds together. "And it adds green to the verde." 
 
Meanwhile, Marshall could not have picked a better pepper than the jalapeno for his verde. The jalapeno has a smoky flavor, even fresh off the vine, is found on Mexican and New Mexican menus alike, and is the official state pepper of Texas. As for the cilantro, you either love it or hate it. Haters can substitute parsley. 
 
The power of the pungent green herb is matched by the jalapeno, garlic and vinegar, resulting in a bright sauce that, juxtaposed against the heavier parts of the pizza, creates magic in your mouth as you eat. Haters of cilantro can substitute parsley. 
 
As soon as he opened Biga, in 2006, Marshall began making the most of his 600-degree oven. "My cooking style is Old World," he says. "We have only one heat source in this entire restaurant. Everything happens in the oven."
 
Marshall's Meatball Verde pizza is so popular there would be a protest if it left the summer menu. It was inevitable that he'd end up in the finals of "Guy Fieri's Pizza Play-Offs," on Food Network. 
 
I asked Marshall if he would show me a simple way of using his verde for those of us without pizza ovens at home. He suggested roasted roots, tossed with breadcrumbs baked into a gratin. 
 
As potatoes, cauliflower and carrots roasted in the oven, Bob got to work converting a house-made focaccia into breadcrumbs, slicing, toasting and blending the bread into pieces. 
 
It was the Biga kitchen, after all, and nothing makes it out of there without at least a kiss of "biga," an Italian word that refers to the starter from yesterday's dough, a little of which is used every morning by Italian bakers like Marshall in the mixing of a new batch.  
 
"You could make an argument that we are a bakery," he says. "We make 300 pounds of dough every day."
 
Finally, he made the verde in a Vitamix. it took less than five minutes. 
 
He combined the roots, crumbs and verde, and baked until it had a golden crust. That, technically speaking, is a gratin, and cheese is optional. Marshall wasn't in the mood that day, but he agreed it wouldn't be verde gratuitous to add cheese to the gratin. 
 

Verde Gratin
 
The gratin can be made vegan, as we did that day, or with added proteins. I have been enjoying it with cheese curds and chopped bits of browned meat. Marshall recommends mushrooms as a meaty alternative. 
 
Two servings
 
2 cups carrots, cut into inch rounds 
2 cups potatoes, cut into inch chunks
2 cups cauliflower, separated into florets about an inch across 
1 teaspoon salt 
2 teaspoons pepper
3 tablespoons olive oil
2 cups bread crumbs
½ cup Biga Verde (recipe follows)
Optional: proteins, like cheese, meat or mushrooms
 
Soak the cut potatoes for 30 minutes in water, and drain. Toss the carrots and potatoes in olive oil, salt and pepper, and spread out evenly on the pan, filling all space. Bake at 450 until everything is golden, soft and puffy. Don't stir. 
 
When the roots are cool enough to work with, toss them with the crumbs, verde and optional proteins, and bake until the top develops a crust. 
 
Biga Verde
yield: 2 cups
 
Gratin is but one vehicle for this verde. It's a great finishing sauce, dip, marinade and dressing. Just don't overdo it, as a little goes a long way. Cilantro haters and skeptics should substitute parsley. 
 
½ cup onion, thinly sliced
3 jalapenos, seeded and sliced
1 cup rice vinegar
2 teaspoons cumin
1 fat garlic clove
2 tablespoons olive oil
¾ pound cilantro, including stems as long as they are not too woody
1 teaspoon salt
 
Add the sliced jalapenos and onions to the rice vinegar, either a few hours or a few days before making the verde, which will allow the onions and jalapenos to pickle.
 
Add the jalapenos, vinegar and onions to a blender, along with the rest of the ingredients, and blend until smooth. Will last up to a week, well-sealed in the fridge.