Using a bamboo steamer, or any steamer of your choice, steam the carrots, mushrooms, yellow squash, and zucchini, if using sliced zucchini. This usually takes anywhere from 5-8 minutes depending on the method of steaming.
Do not overcook; you don’t want them to become mushy once added to the sauce.
If making zoodles, add them to a colander and sprinkle with salt, let them stand in the sink for at least 10 minutes to draw out some of the water. When ready, pat them dry with paper towels.
While the vegetables are steaming, heat some cooking fat, coconut milk (start with a 1⁄2 cup), salt and pepper to taste over medium-high heat until boiling.
Turn down the heat to medium and add in the pesto and lemon juice, stir until well incorporated. Taste, and adjust the seasoning or add additional coconut milk to your liking.
Bring the sauce to a simmer and add the zoodles, if using, and gently mix with tongs, cook for 1 to 2 minutes.
Next, add the spinach and cook until wilted.
Add the remaining vegetables and gently mix. If you’d like, let the vegetables simmer in the sauce for a few minutes, just make sure they don’t overcook.
Transfer to a serving bowl and serve warm.