Keep the eggs refrigerated below 40°F while you prep the vegetables. Cut the patty pan squash into 1/2-inch cubes and dice the red onion into 1/4-inch pieces. Then mince the jalapeño and toss everything with smoked paprika, kosher salt and black pepper. Allow 8 to 10 minutes for this prep. Use a rocking knife motion so the squash pieces stay even. The cubes should look firm and dry with pale green skins and creamy centers. You'll smell the jalapeño as soon as it's finely cut. Oversized pieces stay watery while tiny pieces scorch before the eggs are added. Don't leave the seasoned squash sitting longer than 10 minutes or salt pulls out too much moisture. Even pieces brown together because moisture leaves at the same rate.

Heat a 10-inch cast-iron skillet over medium-high heat until the cooking surface reaches about 400°F. Add extra-virgin olive oil and spread the squash mixture into one loose layer. Cook for 8 to 10 minutes and turn the cubes every 2 minutes with a broad scraping motion. Keep the pieces moving between the center and outer edge so they brown without steaming. By minute 8 the squash edges should turn deep golden while the centers stay tender. You'll hear the sharp sizzle soften as water cooks away and the onion smells sweet. Go past 10 minutes and the smallest cubes collapse into mash. (My first batch stayed crowded - it steamed and tasted flat. A single layer fixed it.) High heat drives off moisture before the squash loses its shape.

Lower the skillet to medium-low heat, about 300°F, and spread the browned squash around the outer half. Whisk the eggs with whole milk for 30 seconds until no clear streaks remain. Pour them into the center and drag a silicone spatula slowly from edge to center every 15 seconds. Fold in sharp cheddar during the final minute and cook 3 to 4 minutes total. The eggs should form soft yellow curds that still look slightly glossy. The sharp cheddar melts into thin orange ribbons while squash cubes remain distinct. If the skillet stays near 400°F the eggs turn dry before the cheese melts. Pull the filling when the curds barely hold together because residual heat keeps working. Gentle heat limits protein tightening so the eggs stay tender.

Transfer the egg and squash filling to a medium white bowl and cover it loosely. Set a large rectangular cast-iron griddle over medium heat, about 350°F. Warm the 8 flour tortillas in batches for 20 to 30 seconds per side. Rotate each one a quarter turn halfway through. Stack them as they leave the griddle so trapped steam keeps every tortilla flexible. Each tortilla should develop a few tan blisters while staying pale and soft. You'll smell toasted wheat when the first side is ready and the edges bend without cracking. Leave them longer than 40 seconds per side and they become stiff. Don't skip the stack because exposed tortillas dry in minutes. Brief direct heat softens the fat without turning the tortillas brittle.

Work while the filling stays above 140°F. Spoon about 1/3 cup into each warm tortilla and fold each one into a soft U shape. Add avocado slices along one side and spoon 1 tablespoon salsa roja over each taco. Then scatter cotija and cilantro unevenly across the tops. Finish all 8 tacos within 5 minutes and serve with lime wedges. The tacos should look full but not packed and the fillings should sit above the folds. Soft eggs and golden squash contrast with cool avocado and bright red salsa. Overfill them and the tortillas split at the base. Wait longer than 10 minutes and steam makes the bottoms damp. Assemble just before serving because warm tortillas absorb moisture quickly.