Cheesy Skillet Kimchi Potatoes

Name: Cheesy Skillet Kimchi Potatoes
Ingredients: 4 cloves garlic; 1 1/2 pounds Yukon gold or russet potatoes; 1/2 large red onion; 2 tablespoons canola oil; 1 1/4 teaspoons kosher salt; 1/2 teaspoon ground black pepper; 2 medium scallions; 1 medium bunch Swiss chard, mature spinach, or beet greens (about 10 ounces); 4 ounces sharp cheddar cheese; 1 packed cup napa cabbage kimchi; 4 slices thick-cut bacon (about 5 ounces); 4 burrito-sized flour tortillas, warmed (optional)