Accountant-turned-recipe writer Nagi Maehashi, the “voice, cook and eater” behind the RecipeTin Eats website, is on a mission to solve the “what can we have for dinner?” dilemma.

Her first cookbook, Dinner, was the top-selling book in Australia last year, and her new cookbook, Tonight, will hit the shelves on October 15.

As a busy woman (Maehashi also runs RecipeTin Meals, a food bank that has donated more than 270,000 free meals to Sydney’s vulnerable), she has found that herbs and spices take a meal from meh to marvellous.

Spices are so important to her cooking that for Tonight she whittled down her list to a “top 13” (why stop at 10?) that work across almost every type of cuisine.

“I literally created a matrix to come up with my most in-demand spices,” she says. “I wrote the spices down one side and I gave it an extra tick in every recipe it appeared.”

She buys most of her spices from the supermarket, eschewing loyalty to any particular brand and choosing whichever is on special that day. “I want my recipes to be accessible, and I just want to make sure my recipes taste good with those everyday spices from a supermarket,” she says.

Maehashi decants any spices not already packaged in well-sealed glass jars into airtight containers or jars to prevent moisture getting in and retain freshness. Her Kmart jars and Bunnings spice rack take prime possie on the kitchen bench. “I like to see my spices and grab them instantly, so I’ve never stored them in drawers.”

If you’re a bit suss on your spice being too old, Maehashi recommends the sniff test. “If it doesn’t smell like it’s supposed to smell then you know it’s completely dead. Spices that are too old lose flavour, and it doesn’t matter how much cumin you put into a dish, you can’t taste it, and the dish just gets grainy.”

Here, then, are Maehashi’s essential 13 herbs and spices.

Cayenne pepper

“I use cayenne for a spicy, warm heat,” says Maehashi, who loves this dried chilli pepper for its stable nature. “I find you get consistency of heat from brand to brand, no matter where you buy it.”

She busts out the cayenne when cooking Southern US comfort food, adding fire to marinades and spice rubs (including for barbecue brisket or Carolina pork ribs), and making spice blends for jambalaya and chilli con carne.

Chilli flakes

Earthiness, warmth, and the “little red flecks” are why Maehashi sprinkles chilli flakes on anything from scrambled eggs to “a piece of boring grilled chicken”. She prefers them to black pepper, chilli paste or sriracha.

“I’ll just sprinkle chilli flakes because I just like that little bit of dust,” she says. “I use [them] a lot on pastas. Especially when you make pastas that are family-friendly with no spice, you can sprinkle them on at the end. I love them.”

Cinnamon (ground)

“The thing people never think of is using [cinnamon] in savoury [dishes], and I love it,” says Maehashi. “Tagines, fruit and nut pilafs, and massaman curry – so good!”

She nominates ground cinnamon as a core spice because it’s so “universally useful” but she also tosses cinnamon quills in slow-cooked dishes, for earthiness or “specifically when I don’t want a sauce to be brown”.

Coriander (ground) and cumin (ground)

These are Maehashi’s big two, the most-used spices in her pantry, used for Indian, Mexican, southern American, Brazilian, Thai and African cuisine. She’s chosen the ground versions because “I feel like you can use powder in a more discreet way”.

But she also loves toasting whole cumin and crushed coriander seeds to create a “sizzle dressing”, frying the spices in olive oil to release the aromatics.

“It’s Keen’s, the orange one!” says Maehashi about her favourite Keen’s Traditional Curry Powder. “I am such a curry snob, so I never use bought curry powder in Indian curries or Sri Lankan curries, Pakistani curries, none of the ‘real’ curries.”

Instead, she uses Keen’s for British dishes such as kedgeree, tosses roasted chickpeas in it for a fast salad or mixes it through the mayo for a curried egg sanger.

“It’s a shortcut to make things a little bit more interesting,” she says. “Don’t go curry-posh on me when you’re giving me an egg sandwich; just use Keen’s.”

Garam masala

Maehashi calls this ancient spice blend “curry powder on steroids” and uses it exclusively for “proper” Indian curries, including eggplant curry and chana aloo (chickpea with potato).

“Oh, and biryani. I use it to make biryani with a curry sauce buried under the rice,” she says. “I love biryani. It’s in my new cookbook, it’s in my old cookbook, it’s on my website.”

Garlic powder and onion powder

“Five or 10 years ago, it was really hard to find [garlic or onion powder] in Australia, but they’re definitely staples in supermarkets now,” says Maehashi, who uses these two powders in American ranch dressing.

“It’s so good in spice mixes and rubs. When you put garlic and onion powder in a rub for meat and then pan-fry, it makes all the difference, that’s what I know. It just takes it to another level of deliciousness.”

Maehashi finds the powdered forms “earthier and warmer than fresh garlic and onion”.

Paprika (sweet)

“I’m trying to think of a cuisine that doesn’t use paprika,” says Maehashi, who also uses smoked paprika but favours plain paprika for its versatility.

“My staple spice mix is paprika, garlic and onion powder. That’s a go-to I use all the time.” She suggests two parts paprika, one part onion powder, one part garlic powder, plus salt and pepper.

“You mix them together, sprinkle it on protein [or vegetable], pan-sear it, cook it. Then, while you’re resting it, deglaze the pan with butter or wine or chicken stock and then reduce it and pour it over the protein.”

Dried thyme and oregano

“I love thyme,” says Maehashi. “For me, thyme is pretty similar to oregano in terms of its use as a dry herb.”

She uses thyme and oregano in spices mixes (such as for Caribbean jerk chicken), Mediterranean staples, and for creating a “discreet herbiness” in peasant-style Gallic dishes.

When it comes to oregano, Maehashi says she prefers dried to fresh for its stronger and longer flavour hit, and especially uses it in Mexican classics or as a Greek marinade and on a Greek salad.

Turmeric

“Turmeric is so cool,” says Maehashi. Revered for its potent anti-inflammatory properties, it’s a power ingredient that’s become trendy on social media. “All of a sudden everything’s ‘turmeric this, turmeric that’, ‘golden this, golden that’.”

Maehashi uses turmeric for Indian food and southern Thai marinades. “It just makes everything bright yellow and interesting. It’s so good. I love it.”