Lower the heat to medium-low and add the shallot, garlic and red pepper flakes. Saute, being careful not to burn, until the shallot begins to soften, about 2 minutes.
Add the sundried tomatoes and wine to the skillet. Cook, stirring, scraping up bits until the wine is reduced by half.
Add the pasta, chicken broth, milk, salt and Italian seasoning. Bring to a gentle simmer (you don’t want it to boil) and cook, stirring often, until the pasta is al dente and the liquid is absorbed and creamy, 12 to 15 minutes. (if your pasta is still not done, you may need to add 1/4 cup more liquid and continue to cook until al dente and the sauce is creamy).
Reduce heat to low and stir in the lemon and spinach, two cups at a time, until wilted down. Add the black pepper and parmigiano reggiano and continue to stir until the cheese is melted and combined.
Divide the pasta amongst 4 bowls. Garnish with more parmigiano reggiano fresh parsley if desired.