Preheat the oven to 350 degrees F.

Cut the bread into cubes and spread out on a baking pan.

Bake the bread cubes for 5 to 7 minutes until golden and toasted.

Set toasted bread cubes aside.

Coat a nonstick skillet with canola oil and place over medium-high heat.

Add the chorizo and cook until completely browned, breaking it up with a wooden spoon, about 5 minutes.

Transfer cooked chorizo to a paper towel-lined plate and set aside.

Add the chopped plantains to the skillet and cook until browned, 3 to 4 minutes, stirring often.

Transfer the cooked plantains to a paper towel-lined plate.

In a large bowl, whisk the eggs, add the cooked chorizo and plantains; season with salt and pepper.

Gently stir to incorporate all ingredients.

Melt the butter in the skillet over medium heat.

Add the egg mixture to the skillet, tilting the pan so that the eggs spread out into a thin layer.

Once the eggs start to set on top, cover the skillet and cook until completely set and cooked through, about 10 minutes.

Carefully slide the frittata onto a serving dish, slice into wedges, and serve with bread cubes sprinkled on top.