In a large cast-iron or heavy-bottomed pan, brown chorizo, remove from pan and heat canola oil over high heat. Whisk the flour into the hot oil–it will start to sizzle.

Reduce the heat to moderate, and continue whisking until the roux becomes deep brown in color, about 15 minutes. Add the onions.

Switch to a wooden spoon and stir the onions into the roux. Reduce the heat to medium-low. Continue stirring until the roux becomes a glossy dark brown, about 10 minutes.

Add the chicken to the pot; raise the heat to moderate, and cook, turning the pieces until slightly browned, about 10 minutes.

Add chorizo and remaining ingredients and bring the gumbo to a boil, stirring occasionally. Reduce the heat to medium-low and simmer, uncovered, for 45 minutes. *Use Rotel Mild if you don't like food too spicy.