Cook the bacon in a large soup pot over medium heat until crispy. Remove the bacon and put to the side. If there is excess bacon grease, drain all of it off except for 1 tablespoon.
To the same large pot, add the sausage and onions. Cook until browned.
Add the garlic, celery and potatoes. Season with salt & pepper. Cook for 2 minutes.
Add the chicken broth, pesto, lemon juice, red pepper flakes, and season with salt & pepper. Simmer over medium heat for 15-20 minutes, until the potatoes are tender.
Stir in the kale, and canned corn. Let simmer for 3 minutes.
Stir in the reserved bacon, tortellini, heavy cream and parmesan cheese. Simmer for another 3 minutes. (NOTE: the tortellini will continue cooking and absorbing liquid as the soup sets.)
Serve in bowls with additional parmesan, if desired.