Bring a large pot of water to a boil. Meanwhile, heat oil in a large, deep skillet or dutch oven over medium-high heat. Add onion and shallot and cook until translucent. Add garlic, stir, then cook.
Add ground lamb to the skillet, then season with kosher salt and black pepper. Use a wooden spoon to break lamb apart. Cook until browned on all sides.
When water is boiling, add tagliatelle (or other pasta) and cook according to package directions until al dente. Drain pasta and set aside.
Return to ragu and add fresh ricotta cheese and chopped mint leaves. Stir to combine, taste, then adjust seasoning as needed. Simmer until ready to serve! Serve with freshly grated parmesan cheese and additional chopped mint, as desired.