Chop up all vegetables. Par-cook the bacon in a large stock pot (optional - you can leave the bacon out). Remove and crush it into fine crumbs. Add back to pot.
To the stock pot, add olive oil, all the vegetables, kosher salt, and freshly ground black pepper - and sauté over medium-high heat for approximately 10-15 minutes, or until the veggies start to soften.
Add chicken broth, water, bouillon cubes, and red pepper flakes. Bring to a boil.
Add lentils and additional salt and pepper. Reduce heat to medium, and let soup simmer for approximately 40 minutes, or until lentils are soft.
Check seasonings, and remove from heat. Serve each bowl with some additional freshly ground black pepper, and a splash of balsamic vinegar (optional).