Prepare all ingredients as instructed above.
Heat a pot over medium heat. Add olive oil, then sauté the sliced garlic and diced onion until softened.
Add the ground beef and cook until browned, breaking it into small pieces with a spatula.
Stir in the crushed tomatoes and season generously with salt and pepper. Partially cover with a lid and simmer on low for 30–35 minutes.
Meanwhile, cook the spaghetti according to package instructions until al dente. Drain the pasta, reserving some of the pasta water if desired.
Add the drained spaghetti to the pot with the meat sauce and mix well to coat. Stir in butter and chopped basil until combined.
In a sauté pan over medium heat, melt the butter. Sauté the green peas, stirring occasionally, until hot, about 2–3 minutes. Season with salt and pepper to taste.
In a pitcher or large glass, combine the sparkling water and lemon slices. Serve over ice if desired.
Serve the spaghetti topped with additional grated Parmesan cheese, alongside green peas, sliced pears, and lemon sparkling water.