Heat the olive oil in your Instant Pot using the sauté function on high heat. Once shimmering, add the diced onion and cook for 1-2 minutes until just softened and fragrant. Add the ground turkey and break it apart with a spoon, stirring occasionally. Cook for about 5 minutes until the turkey is mostly browned and no longer pink. I like to let it sit undisturbed for a minute or two between stirs—this helps develop deeper browning and better flavor through caramelization.

Stir in the salt, garlic powder, paprika, oregano, and lemon pepper, mixing well to coat all the turkey with the spices. Let the spices toast for about 30 seconds—this blooms their flavors and prevents them from tasting dusty. Then add the tomato paste and stir constantly for 1-2 minutes, allowing it to caramelize slightly and integrate with the turkey. This step concentrates the tomato flavor and adds rich umami depth to your sauce.

Turn off the sauté function. Pour in the water and add the uncooked penne pasta, stirring just to distribute it evenly in the liquid at the bottom of the pot—this prevents sticking and ensures even cooking. Now carefully pour the marinara sauce over the top of the pasta without stirring it in. This layering technique allows the pasta to cook evenly in the liquid below while the sauce on top remains structured. I find this method prevents the sauce from breaking down and keeps the flavors bright and distinct.

Seal the Instant Pot lid and set the valve to sealing. Cook on high pressure for 5-6 minutes (aim for the shorter time if your pasta is a thinner shape, longer if thicker). The pasta will finish cooking in the residual heat and steam during this brief time.

Once the cook time is complete, carefully use quick release to vent the steam, then open the lid. Gently stir the entire dish together—the sauce and pasta will combine beautifully. Add the spinach, red pepper flakes, and fresh lemon juice, stirring until the spinach wilts into the warm pasta (about 1 minute). The lemon juice adds brightness that cuts through the richness of the turkey and sauce. Taste and adjust seasonings as needed.

Divide the pasta into bowls and top each serving generously with freshly grated Parmesan cheese. Fresh grated cheese melts more smoothly into the warm pasta than pre-shredded versions, which have added anti-caking agents that prevent smooth melting.