Iron-Rich High-Protein Vegetarian Minestrone Soup

Published: February 22, 2026
Paolo RomanoPaolo Romano
Tags: Italian, gluten-free, Vegetarian, High-Protein, Low-Carb, Soup, Weeknight, Minestrone

Protein Minestrone

Hearty low-carb vegetarian minestrone packed with protein and iron from tempeh, lentils, and dark leafy greens.

Prep Time:20 minCook Time:40 minTotal Time:60 minServings:6Difficulty:Medium

Nutrition (per serving)

Calories:320 kcal
Protein:28 g
Carbs:26 g
Fat:12 g

This minestrone is my cozy, iron-forward take on a classic — built to be vegetarian, gluten-free, and low in carbs without skimping on heartiness or protein. I use crumbled tempeh and red lentils for a satisfying, meat-like texture and load the pot with spinach and kale for extra iron and flavor.

It’s the kind of soup that brightens a weeknight and keeps you full: simmered slowly so the lentils soften into the broth, finished with a squeeze of lemon and a sprinkle of Parmesan (optional) to lift the flavors. Serve with a crisp salad or a slice of gluten-free bread for a complete meal.

Ingredients

  • Extra-virgin olive oil:2 tbsp
  • Yellow onion, chopped:1 piece
  • Carrots, diced:1/2 cup
  • Celery stalks, diced:2 pieces
  • Garlic cloves, minced:4 pieces
  • Tempeh, crumbled:12 oz
  • Red lentils, rinsed:3/4 cup
  • Canned diced tomatoes:14 oz
  • Tomato paste:2 tbsp
  • Low-sodium vegetable broth:6 cups
  • Zucchini, diced:2 pieces
  • Kale, stems removed and chopped:2 cups
  • Baby spinach:4 cups
  • Dried oregano:1 tsp
  • Dried thyme:1 tsp
  • Smoked paprika:1/2 tsp
  • Red pepper flakes (optional):1/4 tsp
  • Kosher salt:1 tsp
  • Freshly ground black pepper:1/2 tsp
  • Fresh lemon juice:1 tbsp
  • Grated Parmesan (optional):1/4 cup
  • Fresh parsley, chopped (for garnish):2 tbsp

Instructions

  1. Heat olive oil in a large heavy pot over medium heat until shimmering.

    Olive oil shimmering in a heavy pot
  2. Add the chopped onion, carrots, and celery and cook, stirring occasionally, until softened, about 6 minutes.

    Onion, carrot, and celery softening in olive oil
  3. Stir in the garlic and crumbled tempeh; cook 4–5 minutes until the tempeh begins to brown and absorb the aromatics.

    Crumbled tempeh browning with garlic and vegetables
  4. Add the tomato paste and smoked paprika and cook 1 minute to deepen the flavor.

    Tomato paste and smoked paprika coating tempeh
  5. Pour in the diced tomatoes, rinsed red lentils, and vegetable broth; stir to combine.

    Tomatoes, red lentils, and broth stirred into the pot
  6. Bring to a gentle boil, then reduce heat and simmer uncovered for 20–25 minutes until lentils are tender and the flavors have melded.

    Lentil tomato soup simmering with small bubbles
  7. Add the diced zucchini, chopped kale, and baby spinach and simmer 5–7 more minutes until the greens are wilted and zucchini is tender.

    Zucchini, kale, and spinach wilting into minestrone
  8. Season with dried oregano, thyme, salt, pepper, and red pepper flakes to taste; adjust seasoning as needed.

    Herbs, pepper, and red flakes sprinkled over soup
  9. Remove from heat and stir in the lemon juice; if using, stir in grated Parmesan for a creamier finish.

    Lemon juice and Parmesan stirred into minestrone
  10. Ladle into bowls, garnish with chopped parsley and an extra drizzle of olive oil, and serve hot.

    Finished minestrone with parsley and olive oil

Tips & Notes

  • For an even higher protein boost, swap half the tempeh for firm tofu or add a dollop of Greek yogurt when serving.
  • If tempeh brand contains grains and you're extremely sensitive, check the label for gluten-free certification or use extra-firm tofu as a gluten-free substitute.
  • Make this ahead — flavors deepen after a day in the fridge. Reheat gently and add a splash of broth if the soup thickens.