To prepare meat loaf, cut bell peppers in half lengthwise; discard seeds and membranes.
Place pepper halves, skin sides up, on a foil-lined baking sheet; flatten with hand. Broil 12 minutes or until blackened.
Place in a paper bag; fold to close tightly.
Let stand for 10 minutes. Peel and finely chop.
Place bell peppers in a large bowl.
Reduce oven temperature to 35
Place about one-fourth of mushrooms in a food processor; pulse 10 times or until finely chopped.
Transfer chopped mushrooms to a bowl. Repeat procedure 3 times with remaining mushrooms.
Heat a large nonstick skillet over medium-high heat.
Add oil to pan; swirl to coat.
Add mushrooms to pan; saut 15 minutes or until liquid evaporates, stirring occasionally.
Add mushrooms to bell peppers. Wipe pan with paper towels.
Add asparagus and onion to pan; saut 6 minutes or until just tender, stirring occasionally.
Add onion mixture to mushroom mixture.
Arrange breadcrumbs in an even layer on a baking sheet; bake at 350 for 10 minutes or until golden.
Add breadcrumbs and the next 8 ingredients (through eggs) to mushroom mixture, stirring well. Spoon mixture into a 9 x 5-inch loaf pan coated with cooking spray; press gently to pack.
Bake at 350 for 45 minutes or until a thermometer registers 15
To prepare topping, combine 2 tablespoons ketchup and remaining ingredients in a small bowl; brush ketchup mixture over meat loaf.