In a large bowl, mix oxtail with bell peppers, onions, ginger, garlic, oregano, allspice, thyme, browning, salt, and pepper. Cover and refrigerate for at least 24 hours, up to 48 hours for deeper flavor.

In a large pot over medium heat, add canola oil and brown sugar. Stir until sugar caramelizes to a light brown.

Add marinated oxtail (reserve extra marinade) and brown on all sides. Work in batches to avoid overcrowding.

Deglaze the pot with reserved marinade, scraping flavorful bits. Return all browned oxtail to the pot.

Add water until meat is just covered. Add extra thyme if desired. Simmer on low for 2?3 hours, until meat is fall-apart tender.

Remove oxtail, shred meat, and discard bones. Skim fat from the gravy and add ketchup (if using). Boil to reduce and thicken, then return shredded meat to the sauce.

In a separate pot, melt butter over medium heat. Whisk in flour to make a roux. Cook for 1?2 minutes.

Gradually add half and half, whisking until thickened (3?4 mins). Stir in garlic, salt, and pepper. Remove from heat and add cheddar and Muenster cheese until melted. Fold in cooked macaroni.

Spoon shredded oxtail and gravy into the bottom of each ramekin. Sprinkle a little shredded cheddar on top. Layer with mac and cheese and finish with more shredded cheddar.

Place ramekins on a baking sheet. Bake at 375?F for 15?20 minutes or until tops are golden and bubbly. Serve hot.