Begin by preheating your oven to 425. Lightly grease a large baking sheet and set aside.
Make your cauliflower rice by cutting cauliflower into florets. Place inside your blender and pulse for just a few seconds until it resembles a rice texture. Do not over pulse or it will become mushy. Arrange in an even layer on half of the pan, saving room for the other vegetables.
Arrange the rest of the vegetables on your pan. Coat with oil and season with salt and pepper. Place the baking sheet in the oven in the middle rack position. Bake for 22-25 minutes, or until the vegetables are golden and roasted.
While vegetables are roasting, make your sauce. Add avocado, garlic, vinegar, cumin, lime juice, water, cilantro, pepitas, and salt in the blender. While blending, slowly add oil. Continue to blend until smooth, adding a bit more water if the dressing is too thick.
Serve the bowl with rice on bottom, then top with veggies. Add in pecans, season with salt and pepper, and top with avocado cilantro sauce.