1. Combine water, vegetable broth, wine, garlic, peppercorns, fennel seeds, coriander seeds, cloves, and bay leaves in a multi-functional pressure cooker (such as Instant Pot®). Add a steamer basket. It's okay if the liquid is higher than the bottom of the basket.

2. Leave veal whole, but trim off any excess fat or skin. Place it into the basket. Add onion and place potatoes on top. Make sure the potatoes aren't touching the liquid.

3. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 12 minutes. Allow 10 to 15 minutes for pressure to build.

4. Meanwhile, prepare the sauce. Combine eggs, drained tuna, anchovies, 3 teaspoons capers, and olive oil in a bowl. Mash into a coarse paste with a fork. Season with salt and pepper and set aside.

5. Release pressure using the natural-release method according to manufacturer's instructions, about 5 minutes. Release any remaining pressure carefully using the quick-release method, about 5 minutes. Unlock and remove the lid. Carefully remove the potatoes and onion; set aside.

6. Remove the veal and allow to cool. Wrap the veal in plastic wrap and refrigerate for 2 hours.

7. Strain and reserve the broth. Add some of the cooled broth to the sauce. Use an immersion blender to blend the sauce until smooth and creamy, adding broth little by little as needed. Refrigerate, reserving the broth in case you need it to thin the sauce before serving.

8. Slice the veal as thinly as possible with a carving knife. Arrange the slices on a plate. Slice the potatoes and onions and arrange them on the plate. Top with tonnato sauce and garnish with remaining capers. Serve cold or at room temperature.

Cook's Note:

The "magatello" cut is part topside and part of the thick flank of the veal, a very lean cut of veal.