Trim and core fennel bulbs (reserve some of the fronds for garnishing). Slice lengthwise into 1/4" strips (see notes for step by step directions), chop shallot and mince garlic.
Heat 1 Tablespoon of olive oil in heavy, wide shallow pan or heat proof casserole over medium heat. Add fennel, season with kosher salt and cracked pepper and cook, stirring occasionally, 5 minutes. Add shallots reduce heat to medium-low. Continue cooking until fennel begins to soften and is golden in spots, about 10 more minutes. Stir in garlic and cook 1-2 minutes, until fragrant.
While vegetables are cooking empty one jar of beans with it's liquid into the container of a blender. Add 3/4 cup heavy cream, 2 Tablespoons of lemon juice and 2 Tablespoons of olive oil. Puree until smooth.
Drain and rinse remaining can of beans and add to the fennel mixture. Stir in pureed beans and season to taste with salt and pepper. Taste and add a little more lemon juice if needed.
In a separate bowl combine panko, parmesan, lemon zest and 3 Tablespoons of olive oil. Combine well using your fingers to distribute olive oil evenly and moisten crumbs. Taste and season with salt and pepper to your preference (you may not need any salt, the parmesan cheese has plenty).
Sprinkle breadcrumb mixture evenly over beans. Slide into hot oven and bake 20 minutes, until top is golden and edges are bubbly.
Sprinkle with chopped fennel fronds and additional thyme if desired.
