Chef Xavier George presents a 6-foot “family dosa,” which is made of rice and lentils and comes spread across two platters. MICHAEL BRYANT / Inquirer Staff Photographer

At the edge of exurbia in Exton, not far from where the Lancaster County farmland meets the Chester County sprawl, two startlingly opposite trends in American dining share a single parking lot.

On one side of the lot sits Cheeseburgers in Paradise, the latest branch of a chain that somehow turns a cheery Jimmy Buffett song into a drearily depressing commissary of hokum. This corny beach bar specializes in day-glo drinks, overcooked burgers laced with seasoning salt, and inexplicable hour-plus waits for tables.

Sounds more like Cheeseburgers in Purgatory to me.

In a strip mall at the other side of the lot is Devi, meanwhile, and the crowds are coming there, too. But not for mainstream American chain fluff. Devi is a destination extraordinaire for ultra-authentic regional ethnic cooking.

This modest restaurant specializes in rarely seen south Indian vegetarian cuisine and has none of the marketing glitz of Cheeseburgers. But judging from the van-loads of Indian families that continuously pour into its mango-colored dining room at 9 p.m. on a Sunday, the branding opportunities are obvious.

How about Dosas in Nirvana?

Dosas are the giant, crispy brown crepes made of ground rice and lentils that are the signature home-food of south Indian cooking - a distinct, rice-based tradition that is finally emerging here from the shadows of more familiar north Indian cuisine. And the dosas issue from Devi's kitchen with a dizzying variety of shapes and fillings alongside dips of tangy sambar lentil stew and cooling white coconut chutney.

Cone-shaped, buttered dosas arrive, standing like dunce caps on a plate, before wide-eyed children. Oval dosas come folded over curried spinach. Masala dosas are curled into tubes around mounds of curried potatoes. Spicy Mysore dosas are folded into pointy triangles. And then there was the amazing family dosa, a five-foot (or longer) roll of crepe spanning the length of two platters. It drew so many envious stares on its way to our table that when it finally landed, I looked up to see a nearby table of 12 grinning at us with a unanimous thumbs-up.

It was a proud moment. And it was well rewarded by chef Xavier George, a native of Tamil Nadu state, whose vivid cooking draws on a broad repertoire of Hindu-inspired vegetarian cuisine that impressed me far beyond the dosas.

Devi owner Bn Vittal says the more elaborate and meat-centric Moghlai cooking of northern India became predominant in the West because British colonies were established primarily in the north. The recent local surge in flavors from southern states such as Kerala and Tamil Nadu is an evolution for American ethnic dining not unlike the emergence of true Szechuan or Shanghai cooking from beneath the familiar Chinese apron of Cantonese.

A visit to Devi's lunch buffet is a primer on an entire world of dishes from the subcontinent that Philadelphians rarely see. There are crisp rounds of deep-fried donuts called medhu vada made from ground lentils and ginger. Like the fluffy steamed idly cakes made from ground rice, these are wonderful when dunked into sambar or hot mulligatawny soup, a chickpea lentil brew racing with cumin and curry leaves.

Coconut is one of the primary ingredients in the south Indian palette - like turmeric, George says, it aids the digestion of spice. It appears at Devi in the ever-present chutney dips, but also in the marvelous "coconut rice," which blends sweet shreds of coconut meat into fragrant rice with crunchy bits of fried lentils, snappy cashews, and sweet onions. Coconut milk is also the base of the khurma curry, softening the gingery green chile punch that cloaks cauliflower and green beans.

Other unusual items on the buffet: a deep-fried pakora of cabbage; a creamy tomato curry filled with chickpeas and tender cubes of homemade paneer cheese; brilliant yellow "lemon rice" tart with fresh citrus juice and mustard seeds; and a saute of snake gourd, a ring-shaped vegetable like zucchini sauteed with turmeric and ribbons of onions.

While the buffet is a bargain (from $7.95 to $11.95), it's worth venturing onto the large menu for variations like the gunpowder idly, which earns its name from an incendiary spice crust flared with red chiles and gingelly (a.k.a. sesame) oil. The puli kozhambu is a rare example of cooking from the state of Tamil Nadu; a deeply tangy gravy steeped from tamarind pulp and ginger filled with whole cloves of roasted garlic.

George also produces superb renditions of some more familiar vegetarian curries. His dal makhani is a simultaneously buttery and earthy ragout of black gram lentils, split yellow peas, and red beans. The malai kufta balls, made of cottage cheese, mashed cauliflower and chickpeas, come in an indulgently creamy gravy flavored with onion paste and fenugreek. The channa masala is a rich, cuminy stew of tender chickpeas, but it's the airy bhatura bread that wows the table, an immense balloon of deep-fried dough that breathes buttery steam when we pierce it.

For dessert, there are crisp balls of syrup-soaked gulab jamun, tart mango mousse, sweet shreds of carrot halwa, and vermicelli floating in milky semiya payasam pudding. Frothy cups of Madras coffee are a wake-up from the food stupor.

For the rest of the well-spiced meal, however, consider bringing a crisp white wine or hoppy IPA, because Devi is BYOB. Otherwise, try the house-made "Nimbu" soda, which is essentially seltzer water blended with lime juice and a pinch of garam masala. The aromatic powder swirls through the glass like a fizzy, spicebox brew, but magically harmonizes with virtually every curry.

Who knows? A glass of Nimbu might even improve a Cheeseburger in Paradise.

Contact restaurant critic Craig LaBan at 215-854-2682 or claban@phillynews.com. Read his recent work at http://go.philly.com/craiglaban.