Ingredients matter. It's a phrase repeated so often by food writers and cooking teachers that it's become clichéd.

Of course, it's in the best interest of writers and teachers to point it out, because the success of a dish typically relies on its ingredients. And an unsuccessful dish reflects poorly on its source.

While the advice seems obvious, it can easily be ignored as you stroll down the grocery store aisles where convenience products and bargain prices can lure you away from quality goods. Like every savvy shopper, I love a good deal. But when that deal turns something delicious into something forgettable or worse, it stops feeling good.

The point becomes even clearer when a dish only has a few ingredients, as is the case with this week's Spaghetti With Olive Oil, Garlic and Spinach.

Start with good pasta. Look for dried spaghetti made from semolina flour. The best pasta has a springy texture with an al dente bite and a matte, rather than shiny appearance. In my experience, Italian brands are usually best.

Olive oil is often a matter of taste, so I recommend that you actually taste yours before using it in this dish. Olive oils can be very mild, with almost no flavor, or very assertive. Do you like yours peppery, with a little bitterness, or more buttery? The fun is in exploring, so shop for oil at a store where you can sample it, or at least one that has someone on staff you can talk to about it.

With garlic, there's only one simple rule: Don't buy it prechopped in a jar. Buy it fresh and chop it yourself. Garlic develops a stronger flavor the more finely it's chopped, and the flavor becomes bitter and sharper the longer it sits. And there's not only garlic in that jar; citric and phosphoric acids are also often added for stabilization and shelf life. That's why jarred garlic typically tastes acrid and even unpleasant. Certainly nothing like the spicy sweetness of fresh garlic.

Baby spinach is easy to buy fresh. It's sold picked through and prewashed in a clamshell container in the produce section, and I'm just fine with that as a convenience product. All you have to do is take a few handfuls and toss them into the skillet. When it's this easy, there's no reason to buy it frozen and chopped.

Parmesan cheese is an ingredient that can go very wrong, very fast. The gold standard for Parmesan cheese is Italian Parmigiano-Reggiano. It is rich, nutty, complex and undeniably delicious and can be found in most grocery stores where the higher-end cheeses are sold, usually near the deli counter. Buy a wedge (look for the name Parmigiano-Reggiano printed in a dot-matrix pattern on the rind) and grate it yourself. The other options, pre-shredded in bags or grated in shelf-staple cardboard cylinders, bear little resemblance in flavor to the real thing and won't behave in the same way when added to a sauce.

Once you've gathered all the elements, the dish takes less than 20 minutes from start to finish, resulting in a much more flavor-packed, nuanced dish than the time commitment would lead you to believe. Because ingredients do matter.

Spaghetti With Olive Oil, Garlic and Spinach

Serves 4.

Note: A close cousin to the iconic Italian pasta dish Spaghetti Aglio e Olio, this dish can be made quickly with just a handful of quality ingredients, making it the perfect dinner any night of the week. From Meredith Deeds.

• 12 oz. spaghetti

• 1/4 c. good-quality olive oil

• 6 cloves garlic, thinly sliced

• 1/4 tsp. salt

• 1/4 tsp. red pepper flakes

• 3 c. baby spinach

• 1/2 c. grated Parmesan cheese (Parmigiano-Reggiano, if possible), plus extra for serving

Directions

Cook pasta al dente, according to package directions. Drain, reserving 3/4 cup of the cooking liquid.

Meanwhile, in a 12-inch skillet, heat the olive oil over medium heat. Add the garlic and cook for 1 to 2 minutes, stirring frequently, until fragrant and lightly golden around the edges, but not browned. Do not overcook. Add the salt and red pepper flakes and cook for 30 seconds more. Carefully add the reserved pasta-cooking water to the skillet and bring to a boil for 1 minute.

Add the drained pasta and Parmesan to the garlic sauce and stir to create a creamy sauce, about 1 to 2 minutes. Add the spinach and toss until slightly wilted. Taste for seasoning and serve warm with extra Parmesan on the side.

Meredith Deeds is a cookbook author and food writer from Edina. Reach her at meredithdeeds@gmail.com. Follow her on Instagram ­at @meredithdeeds.