Heat the olive oil in a large saucepan over medium-high heat. Add 1 1/4 cups onions and 1 tablespoon Essence and cook, stirring, for 3 minutes. Add 1 tablespoon garlic and cook, stirring, for 1 minute. Add the tomatoes, tomato sauce, vinegar, sugar, salt, and crushed red pepper and cook, stirring occasionally, for about 20 minutes, or until the sauce thickens. Add the heavy cream and cook for 5 to 10 minutes, or until thickened and flavorful. Taste the tomato sauce and adjust the seasoning if necessary. Set aside.
Heat a medium skillet over high heat. Add the ground beef, breakfast sausage, the remaining 1 1/4 cups onions, and the remaining tablespoon Essence and cook over high heat, breaking the meat into pieces with the back of a spoon, until the meat is golden brown and the onions are very soft, about 8 minutes. Add the remaining 1 tablespoon garlic and cook, stirring, for 1 minute. Remove from the heat and let cool slightly. Add the rice, black pepper, egg, and 1/4 cup of the tomato sauce and stir until thoroughly blended.
Preheat the oven to 350 degrees F. Ladle 1 cup of the tomato sauce onto the bottom of a nonreactive 9 x 13-inch casserole or baking dish.
Separate the cabbage leaves and cut off the thickest part of the hard spine from each leaf. Spread the leaves on paper towels and pat dry. Working with one at a time, spoon a generous 1/4 cup of the filling into the center of a leaf. Roll up egg-roll fashion, tucking in the ends, and place the roll onto the sauce in the casserole dish, seam side down. Repeat with the remaining leaves (fit the rolls into the casserole in 1 layer.) Pour the remaining tomato sauce over the rolls, cover tightly with aluminum foil, and bake until the rolls are very tender and heated through, about 1 hour.
Makes about 18 rolls, 6 to 8 servings