Prepare the vegetable broth by boiling the tough parts of the asparagus with leek (or onion) and thyme in plenty of water.
Clean the asparagus and separate the tips from the stalks. Cook the stalks with a drizzle of oil, salt, and a little water. Then, blend them with a hand blender to obtain a smooth cream. Reserve the tips.
In a pan, lightly toast the cured ham until it becomes golden and aromatic.
In a pot, melt part of the butter with a little oil and sauté the shallot or onion until tender. Add the rice and toast it until it changes color.
Incorporate the white wine and let it evaporate. Gradually add the hot broth and the asparagus cream, stirring constantly until you achieve a creamy texture and the rice is al dente.
Remove from the heat and add the remaining cold butter, the grated cheese, and some thyme leaves. Mix gently.
Plate the risotto and decorate with the reserved asparagus tips and, optionally, grate over the cooked egg yolks.