4 lbs (about 10 cups diced) root vegetables (use at least 4 different kinds, such as sweet potatoes, any variety of winter squash, green plantain, parsnip, carrot, boniato, etc.), diced into 3/4” pieces
Heat 1-2 Tbsp of olive oil in a skillet over medium-high heat, then add onion. Cook, stirring occasionally until browned, about 10 minutes.
Remove onions from the skillet and place in a 9”x9” casserole dish; set aside. Add another 1-2 Tbsp of olive oil and add summer squash to the pan. Cook, stir- ring occasionally, until browned, about 10 minutes. Add garlic and cook 2 more minutes.
Add broth and wine to the summer squash. Simmer until liquid reduces by two thirds, about 15 minutes. Add salt.
Preheat oven to 400F.
Carefully pour contents of skillet into a blender. Blend on high for 30 seconds to 1 minute, until completely smooth. Taste and add extra salt, if needed. You want this sauce to be a little salty.
Toss diced root vegetables with caramelized onion in the casserole dish. Pour the sauce from the blender all over the root veggies.
Bake uncovered for 50 minutes to an hour, until root veggies are fully cooked. Let sit for 5-10 minutes before serving.