Peel and cut the russet potatoes into 1-inch cubes, placing them in a bowl of cold water to prevent browning. Finely dice the onion into 1/4-inch pieces and dice the ham into 1/2-inch chunks. Cook the bacon in a skillet over medium heat until crispy, about 8-10 minutes, then drain on paper towels and crumble when cool. This prep work ensures everything is ready to go into the slow cooker and allows the bacon to cool so it won't get soggy when added as a garnish.

Drain the potatoes from their water and transfer to your slow cooker. Add the diced onion, ham, cream of chicken soup, chicken broth, water, garlic, pepper, and dried thyme. Stir well to combine all ingredients evenly. Set the slow cooker to low for 6-8 hours (or high for 3-4 hours) and let it cook until the potatoes are completely tender and easily break apart with a spoon. I like to stir the mixture once halfway through cooking to ensure even heat distribution and prevent the bottom from sticking.

About 1 hour before serving (or about 1-2 hours into a high-heat cook), whisk together the flour and milk in a small bowl until smooth with no lumps. This flour acts as a thickener and prevents the milk from curdling when added to the hot soup. Freshly shred the cheddar cheese if you haven't already—shredded cheese melts much more smoothly than pre-shredded varieties which contain anti-caking agents.

Stir the flour-milk mixture from Step 3 into the hot soup, mixing well to incorporate smoothly and activate the thickening properties. Then add the freshly shredded cheddar cheese, stirring constantly until it's completely melted and incorporated into the soup. For a bolder, more complex cheese flavor, I like to add the sharp cheddar (Tillamook or similar) at this final stage—it won't get lost like it would if added earlier. Let the soup simmer for the final 30-60 minutes on low to allow the flavors to meld and the soup to reach the desired consistency.

Ladle the hot soup into bowls and top each serving generously with the crumbled bacon from Step 1, additional shredded cheddar cheese, and fresh green onions sliced on the bias. The warm soup will slightly soften the bacon and melt the extra cheese, creating an authentic loaded baked potato experience.