Brussels Sprouts With Bacon

Name: Brussels Sprouts With Bacon
Ingredients: 4 thick slices bacon, chopped into 1-inch pieces; 1 pound Brussels sprouts, halved; 1/2 medium to large yellow onion, chopped into 1/2-inch pieces; 4 cloves garlic, smashed and roughly chopped; 2 tablespoons extra-virgin olive oil; 1 teaspoon kosher salt, plus more to taste; 1/2 teaspoon freshly ground black pepper, plus more to taste; 1 tablespoon maple syrup; 1 teaspoon apple cider vinegar, plus more to taste; 1/8 teaspoon red pepper flakes, plus more to taste