But when she turned 30, curiosity got the best of her. She took a leave to attend a course at Leiths School of Food and Wine and remembers standing proudly at a London bus stop in her chef's whites.
"I didn't want to take them off," Henry said recently in her open-plan kitchen, the sun touching her glowing cheeks as she recounted the memory. "Every day was a kind of joy."
Two days into the course, Henry left the security of the BBC and stepped into the unknown. Nine books and a slew of honours later, Henry still pauses in disbelief. Her shelves, floors and tables groan with hundreds of cookbooks from some of the biggest names in food, including Alice Waters, Claudia Roden and Ann Willan. Some critics suggest hers may soon stand in their company.
"She is getting closer and closer to doing some really great work," said Molly O'Neill, a former food columnist for The New York Times Magazine, who believes a renaissance is underway in British food writing, in part because Britons are insulated to some extent from the American belief that a large number of followers on social media equates with knowledge. "She's trying to create a niche. It's not an easy task."
Henry considers her rise improbable. She grew up in Northern Ireland, where good cooks were mostly seen as being good bakers. The food was good, but not exactly exotic. An extended trip to France changed that, with her exchange partner schooling her in proper vinaigrette and pot-roasted rabbit. It gave her a sense that there was something beyond the British Isles. She felt connected.
"You can go anywhere with food without going very far at all," she said. "You can stay in London, you can stay in your kitchen, but you can be travelling anywhere."
Moving to London in the mid-1980s was a revelation. There were Italian, Turkish and Greek shops within walking distance. She tried Vietnamese food in the living room of a woman in Little Venice and ate Ethiopian food without cutlery. She'd go across town for the perfect Turkish pepper. She befriended butchers for veal bones.
With some cash from her granny, Henry bought Roden's "A New Book of Middle Eastern Food" and Waters' "Chez Panisse Menu Cookbook." She was transported.
She thought about Roden entertaining Jewish emigres at her family's home in London, taking down their memories and their recipes so neither would be forgotten. She imagined Waters kissed by the Berkeley, California, sunshine, suggesting desserts that were simple, seasonal and elegant — such as a bowl of cherries with a few perfect cookies.
"It was like seeing a painting and saying, 'Oh. My. God!' Look at the way they look at the world," Henry said.
Roden sighs with pride when told of her impact, saying it is an honour to be considered one of Henry's inspirations. She likes that Henry "puts things together that really go together," and combines that with an eye for colour, which is critical in a cookbook.
"Sometimes people overdo things," Roden said. "When you need two flavours, they put in five. She has a good sense of doing it simple."
Henry has earned a reputation for producing beautiful cookbooks with recipes that work, said Andrea Weigl, chairwoman of the James Beard Foundation book awards committee. But the books also have personality, a sense that you hear Henry's voice from across the table as she tells you how the dish came to be. That personality helped win her a Beard nomination this year for her book, "A Change of Appetite: Where Healthy Meets Delicious."
Henry says she found the book hard to write, not just because she had to do a lot of research on the science behind healthy eating, but because it dealt with issues that were very personal.
"It was quite brave in the 'Change of Appetite' book because my weight has been an issue forever," she said. "It was hard to know where to draw the line."
Readers responded to the honesty. At Kitchen Arts & Letters, the New York City bookstore for food lovers, managing partner Matt Sartwell said his customers appreciated that Henry wasn't on some sort of crusade, a paleo diet or such. She experimented, but wasn't going crazy.
"She's not throwing kiwi fruit on pepperoni pizza," Sartwell said. "But when she pulls something non-traditional you get this sense of sitting up straight and saying, 'Wow, that does make sense.'"
She reached back to her roots for her new cookbook — which is focused on chicken — "A Bird in the Hand." Her grandfather was a farmer, primarily of dairy and poultry, and she learned early how to pick the bones right down to the 'oysters' on the underside. And she wants everyone to appreciate the crispy-salty skin of a roast.
In her kitchen in London's leafy Highgate area on a recent June morning, she spoke about her pride in her family. One of her two sons was home sick from school, but he didn't want to venture far with mom giving an interview. Henry flipped from describing her first bowl of hummus to bantering with her son about piano practice to the fact her partner is a scientist — all without pausing for oxygen. She is not exactly shy.
Despite that social gene, Henry, 50, refuses to raise her profile by appearing in front of a TV camera. For someone who started out producing television documentaries, she displays an almost pathological fear of cooking on camera. Still, the Beard nomination and a Cookbook of the Year award from the Guild of Food Writers have brought recognition, something Henry described as "the sort of thing you dream about but never think will ever happen because you're British."
"I wasn't ambitious, I sort of left that behind in telly," Henry said. "I just wanted to do the very best job I could, so I have always put my all into them. And I did want to write books that were worth leaving behind — that has always been important."
SALAD OF JAPANESE GRILLED CHICKEN THIGHS WITH EDAMAME, SUGAR SNAPS AND MISO DRESSING
"Quite addictive. You can get fresh podded edamame beans in supermarkets now as well as frozen. No need to cook the sugar snaps, by the way; they are gorgeously crunchy and sweet in their raw state. I like the contrast here: hot chicken, cool salad," Diana Henry writes in her new cookbook, "A Bird in the Hand." ''The wakame brings a whiff of the seaside, which I love with miso. It reminds me of the Irish seaweed — dulse — that I grew up with. It's entirely optional. I use it dry, crumbled, instead of soaking it."
Start to finish: 30 minutes, plus marinating
For the chicken:
1/3 cup soy sauce
3 tablespoons sake or dry sherry
1 tablespoon dark brown sugar
1 1/2-inch piece fresh ginger, grated
1/4 to 1/2 teaspoon red pepper flakes, to taste
2 cloves garlic, grated
6 small boneless, skinless chicken thighs
2 teaspoons toasted sesame seeds
For the dressing:
1 1/4 tablespoons white miso paste
2 teaspoons pickled ginger, shredded, plus 2 1/2 tablespoons vinegar from the jar, or to taste
2 1/2 tablespoons peanut oil
1 tablespoon water
1/4 teaspoon honey, or to taste
3/4-inch piece fresh ginger, grated
1 garlic clove, grated
For the bean salad:
4 ounces sugar snap peas
8 radishes (mixed colours, if possible), finely sliced
5 1/2 ounces shelled edamame beans, cooked and cooled according to package directions
1/2 ounces micro greens (such as little sprigs of watercress)
1/4 ounce wakame seaweed, crumbled (optional)
In a large bowl, combine the soy sauce, sake, sugar, ginger, red pepper flakes and garlic. Add the chicken, turning to coat. Cover loosely with plastic wrap and refrigerate for 30 minutes (or up to 2 hours). Bring it to room temperature just before cooking.
To make the dressing, in a small bowl whisk together the miso, ginger, ginger vinegar, peanut oil, water, honey, ginger and garlic. Taste for seasoning and sweet-sour balance; adjust as needed, then set aside.
Slice the sugar snaps into strips lengthwise (this looks lovely; you can see the little peas inside peeking out). Put these in a broad shallow bowl with the radishes and edamame.
Heat a grill pan or gill to medium. Lift the chicken out of the marinade and shake off any excess. Grill the chicken, turning frequently, until it is cooked through, about 8 minutes. Cut the chicken across the thighs into broad strips. Set aside.
Add the greens and wakame to the bowl with the snap peas. Add most of the dressing and toss well. Place the chicken on top and drizzle with the rest of the dressing. Scatter with sesame seeds and serve.
Nutrition information per serving: 300 calories; 140 calories from fat (47 per cent of total calories); 16 g fat (2.5 g saturated; 0 g trans fats); 95 mg cholesterol; 970 mg sodium; 12 g carbohydrate; 4 g fiber; 4 g sugar; 27 g protein.
(Recipe adapted from Diana Henry's "A Bird in the Hand," Mitchell Beazley, 2015)