Preheat the oven to 350°F and grease a 10x10-inch casserole dish with nonstick spray; set aside.
Cut the cornbread up into 1-inch cubes and place in a large bowl; set aside.
Heat olive oil in a large skillet over medium-high heat and add in the diced onion, celery, thyme, and sage and cook for about 10 minutes, stirring frequently.
Add in the garlic paste and chopped bacon and cook for 1 additional minute, stirring frequently so the garlic doesn't burn.
Add the vegetable and bacon mixture to the bowl with the diced cornbread, then add in the chives, and salt and toss to combine.
In a separate large bowl, beat together the chicken stock, milk, eggs, and black pepper. Pour the mixture into the bowl with the cornbread along with the melted butter and gently toss to coat.
Transfer the mixture to the prepared baking dish and then bake for 25 to 30 minutes.