The smell of sizzling butter and seared cheese hangs in the air like a cartoon finger, tempting me to order something fried and delicious. Croque monsieur or crab cake — should I go bistro or diner at this Coral Gables charmer?

I am distracted by the perky young chef as she bounces through the dining room.

“You know how I get it so tender?” Shannon Castrec asks a guest. “It cooks in its own fat for 24 hours.” She’s talking, of course, about her velvety duck confit. Though it’s not on the lunch menu, she’s serving it this noon to one of her loyal customers.

At Frenchie’s American Diner, it seems, everyone is a regular. The perpetually smiling husband-wife team of Gabriel and Shannon Castrec run an honest to goodness mom and pop. (Their three children can be spotted doing homework at one of the dozen four-tops in the back.)

The décor, set off by roughly stuccoed walls, is best described as quirky. Wooden tables are swathed in white butcher paper, chairs are covered in red vinyl, and colorful knick-knacks (a flowery watering can, a shopping bag, a baseball cap) swing from the ceiling fans. Music veering from Stevie Wonder to Spanish guitar and The Eagles contributes to the eclectic vibe.

The Miami-born, French Culinary Institute-trained chef turns out first-rate food, both French and American. Her husband, a native of France’s Picardie region, skillfully manages the front of the house with a handshake, hug or kiss for all who enter.

Open so far for weekday lunch and Friday night dinner plus a monthly prix-fixe dinner deal, Frenchie’s is adding Thursday nights to the schedule this month.

Every meal begins with irresistibly warm and crusty baguettes and ever-so-lightly salted butter. A rotating roster of soups and daily fish specials has been spot-on each time I’ve visited.

I am a huge fan of the creamy butternut squash served with a sprinkle of toasted pumpkin seeds. But perhaps the best thing I’ve sampled is the onion soup with a beef stock as deep and rich as mahogany and onions so sweet and soft they melt on the tongue.

The sea bass seared to the color of gingerbread and served over a rustic white bean cassoulet is superb, as is the coq au vin. Salads are notably French in their gentle, slightly salty dressing and clean composition. Tuna niçoise is a favorite, though the Caesar with its perfectly garlicky, house-made croutons would be even better with anchovies.

Steak béarnaise is another standout, as are pencil-thin fries with their salty, hot snap and soft, puffy middle. Moules frite with eraser-sized Mediterranean black mussels in a heady white wine sauce can be super, though one night, with Shannon absent from the kitchen, they were sandy.

The mostly French wine list is simple, serviceable and well-handled, with whites nicely chilled and reds just right.

House-made desserts include dreamy cakes, custardy ice creams and a fine rendition of chocolate mousse that can’t be beat, especially for the price.

I cannot resist the charm of this French-American newcomer, and only hope I can still get a seat once everyone discovers what a gem it is.