Crush the canned whole tomatoes by hand into a bowl.
Select the Sauté setting on the Instant Pot and let the pot heat up for a few minutes before adding the olive oil. Once the oil is hot, add the onion and a pinch of salt. Cook until the onion is browned and completely soft, about 6 minutes.
Add the carrots, garlic, 1 teaspoon of the salt, and the pepper. Cook until the carrots are just starting to soften, 2 to 3 minutes.
Add the lentils, cabbage, water, vegetable bouillon cube, remaining salt, and bay leaves. Stir to combine, pressing the cabbage down with a long spoon to ensure everything is below the Instant Pot’s maximum capacity line. Select the Cancel setting.
Pour the crushed tomatoes on top and stir to combine.
Secure the lid and set the Pressure Release to Sealing. Select the Pressure Cook setting at high pressure and set the cook time to 10 minutes. Allow a natural pressure release.
Open the pot and stir in the vinegar and taste for seasonings, adding more salt and pepper as needed. Serve with bread.