Cook pancetta (or bacon) in a large skillet over medium heat until crispy and the fat is rendered, 4 to 5 minutes. Add sliced fennel, onion, garlic, and oregano; cook, stirring often, until the onions are translucent and the fennel is wilted, about 8 minutes. Add beans and tomatoes; cook, stirring often, for 5 minutes more.
Heat oil in a medium nonstick skillet over medium heat until shimmering. Crack eggs into the pan; cover the pan and reduce heat to medium-low. Cook until the whites are set but the yolks are still runny, 4 to 5 minutes, or until desired doneness.
Divide the bean and vegetable mixture among 4 plates and top each with an egg. Sprinkle with pepper and garnish with basil and fennel fronds, if desired.
