Slice the yellow squash into 1/4-inch rounds and thinly slice the onion into half-moons. Try not to make the squash too thin, as it will release more water and become mushy if sliced too thin. Set both aside on a cutting board, ready to use.

Heat the bacon grease in a large skillet over medium-high heat until it shimmers. Add the sliced onions and cook for about 3 minutes, stirring occasionally, until they become translucent and begin to soften. This develops the base flavor for the dish and allows the onions to release their natural sweetness.

Add the sliced squash to the pan with the onions and cook for 3-5 minutes over medium-high heat, stirring occasionally. I like to let the squash get a bit of color on the edges—it adds a subtle richness to the final dish. Sprinkle in the fresh thyme leaves and garlic powder, stirring to coat the vegetables evenly.

Pour in the chicken broth and immediately reduce the heat to medium. Cover the skillet with a lid and cook for 5-8 minutes until the squash is tender and can be easily pierced with a fork. The broth will create steam and gently soften the vegetables while keeping them from drying out. Once the squash reaches your desired tenderness, remove the lid and season generously with salt and freshly cracked black pepper to taste.