Christine d’Ornano runs Sisley – the ground-breaking plant-based cosmetics brand founded by her parents in 1976 – with her brother Philippe. For the last 20 years, d’Ornano has lived with her husband and three daughters in Ladbroke Grove in London’s Notting Hill, in a colourful, quirky Victorian house that she has decorated with originality and flair. With tastes honed by international travel and having inherited her parents’ flair for decoration, d’Ornano confidently mixes modern, mid-century and antique furniture and accessories, including some finds from nearby Portobello market; she also collects contemporary art and displays it alongside heirloom paintings. This original mix is the perfect backdrop for a relaxed family life and lots of informal entertaining.

D’Ornano remembers her parents entertaining friends and journalists in their magnificent Parisian apartment, “in a way that was always simple and welcoming”, notwithstanding the grand setting. Now, she in her turn, brings together friends, friends’ children, and beauty influencers, usually in the kitchen, where she can add extra leaves to the plain wooden table in order to seat up to 16 guests. “There’s no point in having a beautiful house,” she says, “if you don’t enjoy it to the full.” When she talks about her entertaining style, she uses the word “informal” a lot. On days when she is expecting guests for brunch, she uses pastel-coloured plates hand-painted by the artist Sydney Albertini, with rattan placemats from Morocco, her daughters help her cook scrambled eggs with smoked salmon. “We always have cheese from La Cave à Fromage on Portobello Road; I buy a lot of really good English and French varieties there. We also always have Ladoucette Pouilly-Fumé white wine and dark chocolate in the fridge.”

D’Ornano has turned the library and dining room into a family workspace – and home-schooling hub – but it’s also used occasionally when she gives buffet suppers (“you can invite 40 or so guests without worrying if someone needs to cancel at the last minute”). Here, custom-made chairs upholstered in yellow leather surround a table designed by d’Ornano and her husband. A 1950s Italian floor lamp was found at Alfies Antique Market. These evenings usually end with music, guests spilling out onto the terrace.

In the drawing rooms, D’Ornano’s wizardry at mixing styles and era is most in evidence. A mid-century cocktail table by English architect and designer TH Robsjohn-Gibbings is grouped with a George Smith sofa, a pair of Claude Lalanne chairs, a Utrecht armchair by Gerrit Rietveld, and a rug by The Rug Company. There is a Gary Hume painting over the mantel, a rabbit sculpture by Benedetta Mori Ubaldini, and a Tracy Emin neon piece, Trust Me, above a painting of the Deauville racecourse, which belonged to d’Ornano’s parents. “The one artist whose work I would collect if I could is David Hockney,” says d’Ornano. In the smaller, drawing room (“my favourite room in the house”) whose walls are lined with pink linen, the sofa is by George Smith, and lamps by Serge Mouille flank a photograph of Beirut by Elger Esser.

Family furniture gives the house character and warmth. The desk in the front drawing room originally belonged to d’Ornano’s grandfather and her mother stitched the tapestry seat for the André Dubreuil stool. The bronze sculpture is by the Polish artist Bronislaw Krzysztof. Here the walls are lacquered grey. D’Ornano, who says that if she weren’t doing what she is now, would be a furniture restorer (“seeking out old things and creating something functional out of them”) loves browsing on London’s Pimlico Road, “some of my favourite interiors shops – Rose Uniacke, Jamb, Howe and Soane Britain – are there.”

In her dining room cum library, Christine d’Ornano turns the table into a desk for her children’s homework.