In a large crockpot, combine the sliced kielbasa, green beans, diced onion, and minced garlic.
In a small bowl, mix together the smoked paprika, black pepper, salt, and red pepper flakes (if using). Sprinkle this seasoning mixture over the ingredients in the crockpot.
Pour the chicken broth and olive oil over the mixture in the crockpot. Stir gently to combine all ingredients.
Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the green beans are tender and the flavors have melded.
Serve warm, and enjoy your hearty meal!