Brown the ground beef and onions in large skillet over medium-high heat; drain. Add the taco seasoning as directed on the seasoning package. Then mix in the refried beans.
Preheat the oven to 350°F.
Mix the cream of mushroom soup with 4 ounces of sour cream. Spread enough of the sour cream mixture to cover the bottom of a casserole dish.
Place a scoop of meat on each tortilla, wrap like a burrito, and place seam-side down in the casserole dish. Top with the remaining sour cream and sprinkle with cheddar cheese.
Bake, uncovered, in the preheated oven for 20 to 30 minutes. Garnish with chopped green onions, chopped tomatoes, the remaining sour cream, and Picante sauce if desired.