Set a strainer set over a bowl to catch juices, and pour can of tomatoes into the strainer. If the tomatoes look full (i.e. whole and intact), press on them a bit to release more.
Place onion, jalapeño, and garlic in a blender or food processor and run the machine in short bursts until they’re in smaller bits. Add two-thirds cilantro, drained tomatoes, salt, and juice of one lime and run the machine until the tomatoes are well-chopped but not totally smooth.
Place lentils in a big bowl. Add 1 ½ cups of tomato mixture to the lentils and stir to combine. Taste and add more salsa to taste. Season with salt and black pepper, and add more lime juice if desired. Add avocado, tomatoes, and reserved cilantro and stir gently to combine. Serve with hot sauce and tortilla chips, if you wish.
