Heat a large heavy-bottomed stock pot over medium heat and add the bacon, cooking until the fat renders and it starts to brown
Add the onion, celery and carrots and cook until the vegetables start to soften (if you bacon was lean, you can add a little olive oil to help soften the vegetables)
Then add the butter, garlic, thyme and sage, stirring until fragrant (approximately 45 seconds more)
Raise to medium-high heat and add the vegetable stock and potatoes, bringing to a simmer and cooking until the potatoes are almost cooked (approximately 8 minutes)
Add the zucchini and corn, and season with salt and pepper, continuing to simmer until the vegetables are tender
Optional
For a smoother, richer, more chowder like consistency transfer half of the soup to a blender and purée until smooth, then add the half and half and return it to the pot
Notes
To make this vegetarian, you can omit the bacon. If you're looking for a smokey flavor you can add a little liquid smoke (not too much) or try a chipotle pepper in adobo. It will give it a real kick along with the smoke though so be careful!