Heat olive oil in a large Dutch oven over medium-high heat until shimmering.
Add diced onion and cook 3–4 minutes, stirring occasionally, until soft and glossy.
Push onions aside; add ground beef and cook 5–6 minutes, breaking it up, until no pink remains and browned.
Stir in minced garlic, Italian seasoning, and red pepper flakes; sauté 30 seconds until fragrant.
Soup Simmer
Pour in crushed tomatoes and beef broth; scrape browned bits from the bottom.
Bring to a gentle boil, then add broken lasagna noodles.
Reduce heat to medium; simmer 12–15 minutes, stirring occasionally, until noodles are tender.
Finish
Remove from heat; stir in ricotta and Parmesan until swirled through.
Season with salt and pepper to taste; serve immediately.
Notes
Testing Note (Storage): When reheating from frozen, breaking up noodle clumps keeps pasta tender.For food safety, cool soup no longer than 2 hours before refrigerating; store in airtight containers up to 4 days.Freezes well for 2 months; thaw overnight before reheating.
Nutrition
Serving: 350gCalories: 450kcalCarbohydrates: 35g
Keyword comfort soup, easy dinner, Lasagna soup, one pot lasagna soup, One-pot meals