Preheat your oven to 400°F (200°C).

Dice all your vegetables—green bell peppers, carrots, celery, and onion—into bite-sized pieces.

Drizzle olive oil over the chopped vegetables, then sprinkle with salt, pepper, fresh thyme, and minced garlic. Toss the mixture until evenly coated.

Line a sheet pan with parchment paper, then spread your vegetable mix across it in an even layer.

Roast in the oven for about 25 minutes until tender and caramelized.

Transfer the roasted vegetables to a pot and pour in the low-sodium vegetable broth. Simmer for about 5 minutes.

Stir in the juice of one lemon right before serving.