Heat the olive oil and the butter in a heavy bottomed pot. Add the carrots, celery, and ramps. Cook, stirring, for about 20 minutes, or until very tender.
Add the tomatoes, breaking them up with the back of your spoon, and continue to cook over moderate heat for another half hour.
Stir in the parsley and the basil and season with salt and pepper. Cook a while longer to heat through.
Serve with croutons.