Melt butter in a large pan over medium-high heat. Add onion and corn and sauté for 5-7 minutes until soft stirring occasionally.
Add chicken and continue cooking until chicken is mostly opaque, 3-5 minutes.
Reduce heat to low and add vermouth, stirring vigorously to scrape up any browned bits. Simmer for 20 minutes.
Remove base of blossoms, including anthers and sepals (I just cut off the base and shake everything out). Wash in cold water. Dry as you would salad greens. Slice crosswise into thin rounds (< ¼”).
Turn heat to medium and add tomatoes, cook for 3-4 minutes until barely starting to soften.
Add sliced squash blossoms and cream. Cook for 1 minute further, stirring. Season with salt and pepper to taste.
Serve over hot pasta.