Prep all vegetables; peel potatoes and dice. Rinse and cut green beans.
Warm olive oil in a large pot over medium heat.
Sauté onion, carrots, and celery until softened, 5 to 6 minutes.
Stir in garlic, thyme, and smoked paprika; cook 30 seconds until fragrant.
Add potatoes and green beans; toss to coat with the aromatics.
Pour in diced tomatoes and vegetable broth. Season with salt and pepper.
Bring to a boil, then reduce heat. Simmer gently until potatoes are tender, 18 to 22 minutes.
Stir in corn and peas; simmer 4 to 5 minutes more.
Finish with parsley and lemon juice. Taste and adjust seasoning as needed.