Ensure avocado is ripe; if avocado is firm, ripen in a paper bag, 1-2 days; slice avocado

Preheat oven to 400° + dice onion; wipe mushrooms clean + thinly slice; heat 2 tbsp oil in skillet over high, add mushrooms, onions + sauté 6-7 min til browned + tender; season with salt/pep; add to bowl + mix in 6 tbsp sauce

Slice 2 zucchinis lengthwise + cut off stems; scoop out flesh + mix into veggies; place zucchini boats on a sheet pan lined with foil, season with salt/pep + drizzle lightly with oil

Divide veggies between zucchini halves, top each with 2 tbsp cheese + bake 10-15 min til zucchinis are softened + cheese is melty; garnish with avocado