Place a heavy-bottom skillet over medium heat and add a generous tablespoon of butter, allowing it to melt and foam until bubbly.
Lay the slices of bologna in the hot skillet, giving each enough space to crisp without overlapping. Hear the sizzle as they hit the pan.
Cook the bologna for about 2-3 minutes on each side, watching for golden edges and slight caramelization as the slices curl and crackle.
While the bologna cooks, lightly toast the bread in a toaster or in the same skillet until golden and firm enough to hold the juicy slices.
Once crispy, transfer the bologna slices onto paper towels briefly to absorb excess grease.
Place the toasted bread on a plate, then layer the hot, crispy bologna slices on top, allowing them to slightly melt if adding cheese or to stay juicy and crispy.
Cover with the second slice of bread, gently pressing down to help the flavors meld and the juices distribute.
Let the sandwich rest for a minute to settle, then cut in half if desired, revealing the crispy edges and juicy interior.
Serve immediately while warm, enjoying the crunch of the edges and the savory richness of the fried bologna.