In a large pot or Dutch oven, heat the olive oil over medium heat. Add the diced onion, carrots, and celery. Sauté for about 5-7 minutes until the vegetables are softened.
Add the minced garlic and cook for an additional 1-2 minutes until fragrant.
Stir in the wild rice, vegetable broth, thyme, rosemary, salt, and pepper. Bring the mixture to a boil.
Once boiling, reduce the heat to low, cover, and let it simmer for about 40-45 minutes or until the wild rice is tender.
If using, stir in the chopped spinach and lemon juice, and let cook for an additional 5 minutes.
Remove the pot from heat and stir in the heavy cream until well combined.
Taste and adjust seasoning if needed. Serve hot, garnished with fresh parsley if desired.