I love cooking. That’s why I hated packing school lunches for my three children. If the joy of feeding them is giving them something delicious, then it was joyless to send them off with meals that languished for hours in warm classrooms and were decent at best.

Aside from the almighty peanut butter-and-jelly sandwich, which are sometimes not permitted at schools because of allergies, there didn’t seem to be options that tasted good without reheating, took a reasonable amount of time to put together (sorry, bento box lunches) and could be consumed quickly without any mess.

Entrenched in the daily demands of parenting young children and working, I couldn’t imagine slapping together anything beyond serviceable sandwiches. Once I didn’t have to anymore, I had the time and energy to see another way: that lunches cooked with the intention of being wrapped to eat later will not only hold up over time, but taste even better. (But I’m not so far removed from those brown-bag years as to forget the importance of speed and ease in the kitchen.)

Pesto pasta can be a simple, satisfying lunch — if its standard techniques are adjusted to account for being enjoyed after chilling for a day or more. That deviates from its roots in Genoa, the capital of Italy’s Liguria region, where pesto is served immediately after it’s ground in a mortar with a pestle to deliver basil’s greenest scent. (Pestare, which means “to pound,” is the root word of both pesto and pestle.)

This pesto recipe retains the classic, irresistible combination of basil, garlic, olive oil and Parmesan, but swaps the traditional pine nuts for pumpkin seeds. If buttery pine nuts are a wave hello, pumpkin seeds are a firm handshake. They taste just as rich (but cost far less) and have a bold, earthy flavor. They’re also a rare allergen, and their color bolsters the green hue of pesto.

So does blending fresh basil with a splash of the boiling pasta water. Boiling water deactivates the enzymes that break down chlorophyll, which makes leaves green, and this trick — faster and less fussy than blanching basil by dunking it in boiling water, then in ice water — keeps the pine-green color intact. It also softens the leaves, helping them puree into a smoother sauce.

That bit of boiling water not only helps this dish look appetizing, but it also balances its flavor. Immersing the garlic in the bubbling pot mellows its raw edge, which sharpens after days in the refrigerator. That 30-second step preserves the garlic’s aroma over time while keeping it from overpowering the pesto.

The way the pesto sauce coats pasta is just as important in heightening its flavor. To enjoy this dish right away, it should be tossed with steaming hot noodles just after they’re drained, so that it soaks into the strands. But to enjoy it at room temperature for lunch the next day after sitting in the refrigerator? The pesto should be mixed with pasta that has been rinsed under cold water after draining. Sauces generally cling to starchy pasta, so cooling down the noodles and rinsing them to get rid of that starch helps the pesto sit on top of them instead of sinking into them. That improves the potency of the pesto over time (and works best with curled or ridged pasta that can cradle the sauce, like fusilli or cavatappi).

This dish is one of my children’s favorites, and figuring out a method for day-after pesto pasta was as much for me as for them. It’s not just that it’s a fantastic office (or work-from-home) lunch; it’s that it evokes the childlike delight of finding a surprise treat in your lunch box. A full-blown meal that tastes great straight from the fridge? Yes, it is a wonder. And a quiet night of preparing it is arguably more satisfying, whether you’re going to slip it to a little one or savor it yourself.

Pasta With Pumpkin Seed Pesto

Ingredients:

• Salt and pepper

• 2 garlic cloves, peeled

• 1 pound fusilli or other short, curly pasta

• 1/3 cup pumpkin seeds, plus more for sprinkling

• 1 large bunch basil (4 ounces), leaves and tender stems picked (3 cups)

• 2/3 cup (2 1/2 ounces) finely grated Parmesan, plus more for sprinkling

• 1/2 cup extra-virgin olive oil

• 1 1/2 cups grape or cherry tomatoes, halved (optional)

Directions:

Bring a large saucepan of generously salted water to a boil. Drop the garlic cloves into the boiling water and boil for 30 seconds to temper their sharpness. Use a slotted spoon to transfer the cloves to a food processor or blender.

Drop the pasta into the boiling water and cook until al dente.

While the pasta cooks, add the pumpkin seeds and a pinch each of salt and pepper to the garlic, and process until very finely ground. Scrape the sides of the bowl and add the basil. Scoop 1/4 cup water from the saucepan with the boiling pasta and pour over the basil. Process the basil until ground to a paste. Add the Parmesan and oil, and pulse just until incorporated. Taste the pesto and season with enough salt and pepper to make it punchy.

Drain the pasta and rinse under cool water until room temperature. Shake dry, then return to the saucepan, and add the pesto and tomatoes, if using. Stir well until everything is evenly coated. Season to taste with salt and pepper. Divide among dishes to serve right away or airtight containers to pack for lunch. Sprinkle with pumpkin seeds and Parmesan, and serve, or cover and refrigerate for up to 5 days.

Total time: 25 minutes, serves 4-6.