Creamy Tuscan Pasta

1 lb mild or hot Italian sausage
1 small onion, small-dice
2 tsp minced garlic
1/2 tsp crushed red pepper
1 tsp dried basil
2 Tbsp flour
12 oz chicken stock
14 oz can petite diced tomatoes, drained
10 oz bag baby spinach
1 cup heavy whipping cream, half-and-half, whole milk, or any combination thereof
1 lb dried penne or ziti
2 Tbsp grated parmigiano-reggiano

Bring 4 qts salted water to boil and cook pasta according to pasta directions.  Meanwhile, remove casings from sausage and brown meat in a dutch oven or saucepan over med-hi heat.  After a couple of minutes when there is some rendered fat, add onion, and then when it's browned add spices.  Add flour and saute for 2 minutes.  Add chicken stock and scrape up browned bits from bottom of pan.  Simmer until thick and bubbly.  Add tomatoes (I did not use whole can) and baby spinach, and cook until spinach is wilted.  Just before serving, add whipping cream, hot cooked pasta, and Parmesan.