Arrange a rack in the middle of your oven and line a large baking sheet with parchment paper.
Preheat your oven to 425 degrees f.
Remove the outermost leaves from the cauliflower and rinse off any dirt by running it under water. Pat the excess moisture with a towel, or allow to air dry.
Slice your cauliflower into 1 inch slices; it's ok if the slices don't hold together. Spread the sliced cauliflower into the large baking sheet and lightly spray or brush with oil.
Sprinkle evenly with sea salt and pepper to taste, then garlic and onion powder.
Roast for 20 minutes, turning halfway through until golden brown and crispy on all sides.
Once the florets are done, transfer half of them into an oven dish.
Evenly add half of your beans on top of the florets.
Next add chopped tomatoes, onions, jalapeños, followed by the shredded cheese. Make sure you reserve half of each topping to add to the next layer of cauliflower.
Add the second layer of cauliflower and repeat with remaining toppings.
Place your dish into the oven and roast until cheese is melted, about 6-7 minutes.
Remove your cauliflower nachos from the oven, add a dollop of Greek yogurt and garnish with chopped cilantro.
Serve immediately and enjoy!