Prepare ingredients: dice the zucchini and carrot into uniform roughly 1/2-inch pieces so they cook evenly; finely dice the onion and mince the garlic. Zest then juice the lime and chop the cilantro. Having everything ready (mise en place) keeps the cooking pace steady and prevents burnt garlic or overcooked vegetables.

Warm a large, heavy-bottomed pot over medium heat and add the oil. Add the diced onion and a pinch of salt; sweat the onion for 4–5 minutes until translucent and softened but not browned. Sweating releases the onion's sugars gently to build a sweet, savory base without bitterness.

Add the minced garlic and cook 30–45 seconds, stirring constantly, until fragrant. Garlic burns quickly; a very short cook time ensures you get aromatic depth without bitterness.

Toast the spices: add the ground cumin and chili powder to the pot and stir for 30–60 seconds until aromatic. Toasting the dried spices in fat 'blooms' their oils and converts them from flat to vibrant, giving the broth deeper, more complex flavor.

Add the diced carrot and zucchini and toss to coat with the spiced aromatics. Cook for 2–3 minutes — you want them to start softening and pick up the spice flavor, not to fully cook; they’ll finish in the simmer. This step layers texture and prevents mushy vegetables.

Pour in the canned diced tomatoes (with their juices) and the chicken bone broth. Stir to deglaze the pot, scraping any fond from the bottom — those browned bits are concentrated flavor. Increase heat to bring the soup to a gentle boil.

Once boiling, reduce the heat to maintain a simmer. Add the shredded chicken, salt, and black pepper. Simmer uncovered for 10–12 minutes so the flavors marry and the vegetables reach tender but still-structured doneness. Simmering rather than rapid boiling preserves a clear, flavorful broth and keeps chicken tender.

Taste and adjust seasoning: add more salt, a squeeze of lime, or an extra pinch of chili powder if you want more heat. Bright acidity from lime juice is key to lifting the rich broth — add gradually and re-taste.

Finish with fresh cilantro and lime zest right before serving. Stir lightly to release the herb’s aroma. Adding herbs at the end keeps them bright and green rather than wilted and muted.

Serve hot in warmed bowls with additional lime wedges at the table. A drizzle of extra-virgin olive oil or a few thin slices of avocado (if desired and still paleo) add silky richness.