• Peel and thinly slice enough onion to measure ¼ cup [½ cup]; set aside for the salad. Coarsely chop enough of the remaining onion to measure ¾ cup [1½ cups].
• Cut a small corner from the ground turkey packaging and drain off any excess liquid. Transfer to a plate; pat dry with a paper towel.

In a medium [large] frying pan over medium-high heat, warm 1 tablespoon [2 TBL] oil until hot but not smoking. Stir in the chopped onion, season with salt and pepper, and cook until starting to soften, 1 to 2 minutes. Add the turkey, season generously with salt and pepper, and cook, stirring to break up the meat, until lightly browned but not yet cooked through, 3 to 4 minutes. Stir in the garlic-porcini blend and cook until fragrant, about 30 seconds.
Add the elbow macaroni, milk, and 1 cup [2 cups] water and bring to a boil. Reduce to a simmer, cover, and cook until the turkey is cooked through and the macaroni is just tender, 12 to 14 minutes.
While the turkey skillet cooks, prepare the salad.

• Trim the root end from the romaine heart; coarsely chop the leaves.

In a medium bowl, stir together the honey-mustard vinaigrette base and 2 tablespoons [¼ cup] oil; season to taste with salt and pepper. Add the romaine and sliced onion and toss to combine; season to taste with salt and pepper.

When the macaroni is just tender, sprinkle with the cheddar and add 2 tablespoons [¼ cup] water. Stir until the cheddar is melted and incorporated into the sauce. Remove from the heat and season to taste with salt and pepper.

Transfer the turkey, macaroni, and sauce to individual bowls and serve the salad on the side.