If you want to serve it with my Lemon Marinated Pan-Seared Chicken (which I highly recommend), you can make the chicken first. Then it can be resting while you continue with this pasta recipe.
Cook 2 cups protein pasta according to package directions. Reserve 1/2 cup pasta water before draining, then return pasta to the pot and toss with 1 tablespoon light olive oil to prevent sticking. Cover to keep warm. While pasta cooks, slice the zucchini and yellow squash, dice the onion, mince 3 garlic cloves, and zest and juice 1 lemon.
Heat 2 tablespoons light olive oil in a large skillet over medium-high heat. Add zucchini, yellow squash, and onion. Sauté for 4-5 minutes until vegetables are golden brown on the edges and tender-crisp. Remove to a plate. Add a little more oil if needed and sauté spinach for 1 minute until just wilted. Add to the plate with other vegetables.
In a small blender or food processor, blend 2/3 cup cottage cheese with 1-2 tablespoons milk until completely smooth. This step is crucial for avoiding any lumpy texture in your final sauce.
Melt 2 tablespoons butter in a medium saucepan over medium heat. Add minced garlic and 1 tablespoon Italian seasoning, cooking for 1 minute until fragrant. Add 1 cup of milk but hold back about 2 tablespoons in the bowl. Whisk 2 tablespoons lemon juice with 1 tablespoon cornstarch until smooth. Pour into the skillet and add 1 tablespoon lemon zest and simmer for 2-3 minutes until sauce thickens slightly. Stir in 1/2 cup shredded parmesan cheese until melted. Remove the sauce from heat and whisk in the blended cottage cheese mixture until completely smooth.
Toss the warm pasta with the sauce, then gently fold in the seared vegetables. Optional: Garnish with some additional shredded parmesan cheese on top and serve with chicken.