Rinse turkey breast and pat dry; salt and pepper inside and out. Melt butter in pressure cooker pot over medium-high heat and brown turkey breast, about 5 minutes per side. Remove turkey breast and set aside.
Brown shallots and onions in remaining butter and drippings in pot. Return turkey breast, skin side up, on top of onions. Mix all remaining ingredients other than beans and pour over turkey breast. Seal pressure cooker and bring to full/high pressure; cook at high pressure for 40 minutes. Remove from heat and allow to remain sealed for at least 10 minutes to let pressure dissipate naturally.
Open pressure cooker and remove turkey breast; set aside tented with foil to keep warm. Add beans to juices in pot and heat over medium-high heat to reduce juices and heat beans through. Carve turkey breast and serve with a spoonful of beans and crusty bread for dipping.