Place the stainless steel inner pot inside the Instant Pot®. Press Saute, set the time to 6 Minutes and add the olive oil. Once hot, add the onion, paprika and garlic. Stir constantly while cooking.
Press Saute and set the time for 2 Minutes. Add the tomato puree, salt and pepper, and hot sauce. Add the lentils, stir until the time is up and add the vegetable broth.
Close and lock the Instant Pot® lid. Make sure the steam release handle is turned to Sealing. Press Pressure Cook, pressure level High, and set time to 15 Minutes.
Once the time is up, press Cancel and then turn the steam release handle to Venting. Once all the pressure is released, open the lid and add the mustard and honey. Stir everything well.
Butter inner side of both bread halves and toast in a frying pan. Put a teaspoon of butter in a separate pan and fry an egg.
To assemble, spread mayonnaise on inner sides of the toasted bread. On the bottom piece, lay some lettuce leaves, then the vegetarian mixture of lentils, melted cheese and the fried egg. Top with bread and enjoy!