IF there’s ever been a decent rule for Monday to Friday mealtimes, it should be Rukmini Iyer’s. “Weeknight dinners should be nice, but low effort,” says the food stylist and cook, over her homemade Bourbon biscuits.

The 33-year-old, who you’re likely to recognise as a contestant on MasterChef 2013, has gone and written a whole cookbook packed with recipes that fits this bill.

The Green Roasting Tin is the vegetarian and vegan follow-up to her debut, The Roasting Tin, created for time-poor home cooks. It hinges on chucking a whole load of ingredients into a single tin and roasting it all into speedy, tasty, flavourful life.

The idea for it, she recalls, was triggered by tacos and getting home absolutely shattered from work, in no mood to cook. “I’m on my feet all day styling – it’s a bit like cheffing, you never sit down – but I like eating something fresh when I get in, but I didn’t want to stand and stir because I’d been standing all day.”

So instead, she grabbed all the ingredients she needed for tacos, popped them in a tin, and “blasted it all under the grill”. From then on, her frying pans pretty much knew their days were numbered.

In the book, you’ll find warm Indonesian gado gado potato salad that is pure assembly, drizzled with a quick peanut sauce; an earthy leek and puy lentil gratin with a crisp, cheesy topping; and scored aubergines slathered in miso.

“Because it’s all roasted, you think it might be quite heavy and not fresh, but there’s so many fresh things you can just throw on top afterwards,” muses Iyer. It’s all about layers, she explains. “You want colour, you want a variety, and you want texture. No using curly parsley as a garnish like they did at school!”

Iyer cooked in a casual way at university, but it was while studying for a law conversion degree – which she hated – that food as a career began to occur to her. She went from drawing meal ideas in her margins during lectures, to graduating, putting down a deposit for cookery school, and then getting a call the next day to say she’d been picked to appear on MasterChef. since then, she’s worked in the kitchens of Michelin-starred chefs Tom Kitchin and Raymond Blanc at Le Manoir.

While her whole family’s now veggie, she tends to eat plant-based meals four nights a week, and the rule is: “I want to not miss meat when I’m eating something veggie.”

and when she does buy meat, it’s almost always free range and organic (“I don’t want to eat unhappy meat”). However, Iyer’s fully aware that’s not an economically viable option for all. “I appreciate that I’m in a position to do that,” she explains, “but not everyone is – you can’t ram that stuff down peoples’ throats.”

And so, this latest recipe collection is the mid-point on a Venn diagram that provides weeknight supper answers – and support – whether you’re carnivorous, vegetarian, flexitarian, rushed for time, on a budget, or just lack confidence in the kitchen.

l The Green Roasting Tin: Vegan And Vegetarian One Dish Dinners by Rukmini Iyer is published by Square Peg, £16.99.